Table Of Contents<\/h3>\n\n- 1. Introduction<\/a><\/dt>\n
- 2. Technologies Used<\/a><\/dt>\n
- 3. Spring-boot Application<\/a><\/dt>\n
- \n
\n- 3.1. Groovy Dependency<\/a><\/dt>\n
- 3.2 Groovy Folders<\/a><\/dt>\n
- 3.3 Groovy Spring Application<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 4. Java and Groovy<\/a><\/dt>\n
- \n
\n- 4.1 Payroll Interface<\/a><\/dt>\n
- 4.2 Java Classes<\/a><\/dt>\n
- 4.3 Groovy Classes<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 5. Demo Java vs Groovy<\/a><\/dt>\n
- 6. Spring and Groovy<\/a><\/dt>\n
- \n
\n- 6.1 Spring Properties<\/a><\/dt>\n
- 6.2 POGOs<\/a><\/dt>\n
- 6.3 Address Service<\/a><\/dt>\n
- 6.4 Groovy Spring Application<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 7. Demo Spring Groovy Application<\/a><\/dt>\n
- 8. Spring Groovy – Summary<\/a><\/dt>\n
- 9. Reference<\/a><\/dt>\n
- 10. Download the Source Code<\/a><\/dt>\n<\/dl>\n<\/div>\n
<\/a>1. Introduction<\/h2>\nApache Groovy<\/a> (Groovy) is an object-oriented dynamic programming language for the Java platform. It is dynamically compiled to the Java Virtual Machine (JVM) bytecode, and inter-operates with other Java source codes and libraries. Groovy is written in Java. The first version 1.0 was released in 2007 to help developers to write a simple, elegant source code instead of the complicated Java code.<\/p>\nSpring Framework<\/a> (Spring) is a Java application framework that provides many useful services for building applications. Spring 1.0 was released in 2004. Spring has supported Groovy fully since version 4 in 2013.<\/p>\nSpring boot<\/a> defines a list of starter projects which each project includes a set of default component dependencies and automatic configuration of components.<\/p>\nIn this example, I will create a Spring boot application which utilizes Spring’s features in Groovy.<\/p>\n
<\/a>2. Technologies Used<\/h2>\nThe example code in this article was built and run using:<\/p>\n
\n- Java 1.8.101 (1.8.x will do fine)<\/li>\n
- Maven 3.3.9 (3.3.x will do fine)<\/li>\n
- Eclipse Mars (Any Java IDE would work)<\/li>\n
- Spring boot 1.5.10.RELEASE<\/li>\n
- Groovy 2.4<\/li>\n<\/ul>\n
<\/a>3. Spring-boot Application<\/h2>\nThe easiest way to generate a Spring-boot application is via the Spring starter tool<\/a>. Please check my other article here<\/a> for more details. A maven project will be generated and downloaded to your workstation. Import it into your Eclipse work space. You should have no errors on building it and running it as a Spring Boot Application.<\/p>\nWe will change it to a Groovy spring application with three steps:<\/p>\n
\n- Add a Groovy dependency in the
pom.xml<\/code><\/li>\n- Add a Groovy source folder<\/li>\n
- Change Spring Application to a Groovy class<\/li>\n<\/ol>\n
<\/a>3.1 Groovy Dependency<\/h3>\nThe generated pom.xml<\/code> does not include the Groovy library. We will add it as a dependency.<\/p>\npom.xml<\/em><\/span><\/p>\n<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<project xmlns=\"http:\/\/maven.apache.org\/POM\/4.0.0\" xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n\txsi:schemaLocation=\"http:\/\/maven.apache.org\/POM\/4.0.0 http:\/\/maven.apache.org\/xsd\/maven-4.0.0.xsd\">\n\t<modelVersion>4.0.0<\/modelVersion>\n\n\t<groupId>jcg.zheng.demo<\/groupId>\n\t<artifactId>groovy-spring<\/artifactId>\n\t<version>0.0.1-SNAPSHOT<\/version>\n\t<packaging>jar<\/packaging>\n\n\t<name>groovy-spring<\/name>\n\t<description>Demo project for Spring Boot<\/description>\n\n\t<parent>\n\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t<artifactId>spring-boot-starter-parent<\/artifactId>\n\t\t<version>1.5.10.RELEASE<\/version>\n\t\t<relativePath\/> <!-- lookup parent from repository -->\n\t<\/parent>\n\n\t<properties>\n\t\t<project.build.sourceEncoding>UTF-8<\/project.build.sourceEncoding>\n\t\t<project.reporting.outputEncoding>UTF-8<\/project.reporting.outputEncoding>\n\t\t<java.version>1.8<\/java.version>\n\t<\/properties>\n\n\t<dependencies>\n\t\t<dependency>\n\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t<artifactId>spring-boot-starter-web<\/artifactId>\n\t\t<\/dependency>\n\n\t\t<dependency>\n\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t<artifactId>spring-boot-starter-test<\/artifactId>\n\t\t\t<scope>test<\/scope>\n\t\t<\/dependency>\n\t\t<dependency>\n\t\t\t<groupId>org.codehaus.groovy<\/groupId>\n\t\t\t<artifactId>groovy-all<\/artifactId>\n\t\t<\/dependency>\n\t<\/dependencies>\n\n\t<build>\n\t\t<plugins>\n\t\t\t<plugin>\n\t\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t\t<artifactId>spring-boot-maven-plugin<\/artifactId>\n\t\t\t<\/plugin>\n\t\t<\/plugins>\n\t<\/build>\n\n<\/project>\n<\/pre>\n<\/a>3.2 Groovy Folders<\/h3>\nThe generated project has a Java<\/code> source folder. We will add two folders: src\/main\/groovy<\/code> and src\/test\/groovy<\/code>. Then we will include them as the build resources.<\/p>\n\n![\"spring](\"http:\/\/examples.javacodegeeks.com\/wp-content\/uploads\/2018\/03\/groovy-spring.jpg\")
<\/a>Figure 1 Project Structure<\/figcaption><\/figure>\n<\/div>\n<\/a>3.3 Spring Framework Application in Groovy<\/h3>\nThe generated GroovySpringApplication<\/code> is a Java<\/code> class. We will change it to a Groovy<\/code> class and move it under the src\/main\/groovy<\/code> folder.<\/p>\nYou can execute mvn install<\/code> to build it and then run it as a Spring boot application.<\/p>\n<\/a>4. Java and Groovy<\/h2>\nWe will define Payroll<\/code> interface and implement it with both Java<\/code> and Groovy<\/code> and compare their performance.<\/p>\n<\/a>4.1 Payroll Interface<\/h3>\nDefine Payroll<\/code> interface to calculate the department’s budget based on the time period.<\/p>\nPayroll.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.service;\n\nimport java.math.BigDecimal;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\n\npublic interface Payroll {\n\n\tBigDecimal caculateBudget(JDepartment department, BudgetType type);\n\tBigDecimal caculateBudget(GDepartment department, BudgetType type);\n\n}\n<\/pre>\nNote<\/strong>: It defines caculateBudget<\/code> method for both Java Department and Groovy Department. We use it to demonstrate the method’s performance.<\/p>\nDefine BudgetType<\/code> enum<\/code> for four time periods.<\/p>\nBudgetType.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport java.math.BigDecimal;\n\npublic enum BudgetType {\n\n\tYEARLY, QUARTERLY, MONTHLY, WEEKLY;\n\n\tpublic BigDecimal workingHours() {\n\t\tBigDecimal workingHours = new BigDecimal(0);\n\t\tswitch (this) {\n\t\tcase YEARLY:\n\t\t\tworkingHours = new BigDecimal(2080);\n\t\tcase QUARTERLY:\n\t\t\tworkingHours = new BigDecimal(520);\n\t\tcase MONTHLY:\n\t\t\tworkingHours = new BigDecimal(173.34);\n\t\tcase WEEKLY:\n\t\t\tworkingHours = new BigDecimal(40);\n\t\t}\n\t\treturn workingHours;\n\t}\n\n}\n<\/pre>\n<\/a>4.2 Java Classes<\/h3>\nIn this step, we will create three Java classes to implement the Payroll<\/code> interface.<\/p>\nDefine a department class which contains a list of employees.<\/p>\n
JDepartment.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport java.util.List;\n\npublic class JDepartment {\n\tprivate int id;\n\n\tprivate List employees;\n\n\tpublic List getEmployees() {\n\t\treturn employees;\n\t}\n\n\tpublic void setEmployees(List employees) {\n\t\tthis.employees = employees;\n\t}\n\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\n\tpublic void setId(int id) {\n\t\tthis.id = id;\n\t}\n}\n<\/pre>\nDefine an employee class which contains the employee’s first name, last name, and hourly pay rate.<\/p>\n
JEmployee.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport java.math.BigDecimal;\n\npublic class JEmployee {\n\tpublic JEmployee() {\n\t\tsuper();\n\t}\n\n\tprivate String firstName;\n\tprivate String lastName;\n\tprivate int id;\n\tprivate BigDecimal hourlyRate;\n\n\tpublic BigDecimal caculatePay(BigDecimal hours) {\n\t\treturn hourlyRate.multiply(hours);\n\t}\n\n\tpublic String getFirstName() {\n\t\treturn firstName;\n\t}\n\n\tpublic void setFirstName(String firstName) {\n\t\tthis.firstName = firstName;\n\t}\n\n\tpublic String getLastName() {\n\t\treturn lastName;\n\t}\n\n\tpublic void setLastName(String lastName) {\n\t\tthis.lastName = lastName;\n\t}\n\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\n\tpublic void setId(int id) {\n\t\tthis.id = id;\n\t}\n\n\tpublic BigDecimal getHourlyRate() {\n\t\treturn hourlyRate;\n\t}\n\n\tpublic void setHourlyRate(BigDecimal hourlyRate) {\n\t\tthis.hourlyRate = hourlyRate;\n\t}\n\n}\n<\/pre>\nImplement the Payroll<\/code> interface’s two methods to calculate a given department’s budget.<\/p>\nJPayrollImpl.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.service.impl;\n\nimport java.math.BigDecimal;\nimport java.time.Duration;\nimport java.time.Instant;\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.stereotype.Component;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\nimport jcg.zheng.demo.groovyspring.service.Payroll;\n\n@Component(\"javaPayroll\")\npublic class JPayrollImp implements Payroll {\n\n\t@Override\n\tpublic BigDecimal caculateBudget(JDepartment department, BudgetType type) {\n\t\tInstant start = Instant.now();\n\n\t\tList values = new ArrayList();\n\t\tdepartment.getEmployees().forEach(emp -> values.add(emp.caculatePay(type.workingHours())));\n\n\t\tBigDecimal result = values.stream().reduce(BigDecimal::add).get();\n\n\t\tInstant end = Instant.now();\n\n\t\tSystem.out.println(\"Java caculateBudget for JDepartment took \" + Duration.between(start, end));\n\n\t\treturn result;\n\t}\n\n\t@Override\n\tpublic BigDecimal caculateBudget(GDepartment department, BudgetType type) {\n\t\tInstant start = Instant.now();\n\n\t\tList values = new ArrayList();\n\t\tdepartment.getEmployees().forEach(emp -> values.add(emp.caculatePay(type.workingHours())));\n\n\t\tBigDecimal result = values.stream().reduce(BigDecimal::add).get();\n\n\t\tInstant end = Instant.now();\n\n\t\tSystem.out.println(\"Java caculateBudget for GDepartment took \" + Duration.between(start, end));\n\n\t\treturn result;\n\t}\n\n}\n<\/pre>\nCreate a Junit test class for JPayrollImp<\/code>. <\/div> <\/div><\/p>\nJPayrollImpTest.java<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.service.impl;\n\nimport static org.junit.Assert.*;\n\nimport java.math.BigDecimal;\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.junit.Test;\nimport org.junit.runner.RunWith;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.beans.factory.annotation.Qualifier;\nimport org.springframework.boot.test.context.SpringBootTest;\nimport org.springframework.test.context.junit4.SpringRunner;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.GEmployee;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\nimport jcg.zheng.demo.groovyspring.model.JEmployee;\nimport jcg.zheng.demo.groovyspring.service.Payroll;\n\n@RunWith(SpringRunner.class)\n@SpringBootTest\npublic class JPayrollImpTest {\n\n\t@Autowired\n\t@Qualifier(\"javaPayroll\")\n\tprivate Payroll javaPayroll;\n\n\t@Test\n\tpublic void test_JavaPayroll_caculateBudget_for_JDepartment_yearly() {\n\t\tJDepartment dept = new JDepartment();\n\n\t\tList reports = new ArrayList();\n\t\treports.add(buildJEmployee(\"Mary\", \"Zheng\", new BigDecimal(20)));\n\t\treports.add(buildJEmployee(\"Alex\", \"Zheng\", new BigDecimal(10)));\n\t\treports.add(buildJEmployee(\"Allen\", \"Zheng\", new BigDecimal(8)));\n\n\t\tdept.setEmployees(reports);\n\n\t\tBigDecimal budget = javaPayroll.caculateBudget(dept, BudgetType.YEARLY);\n\t\tassertTrue(budget.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\t@Test\n\tpublic void test_JavaPayroll_caculateBudget_for_GDepartment_yearly() {\n\t\tGDepartment dept = new GDepartment();\n\n\t\tList reports = new ArrayList();\n\t\treports.add(buildGEmployee(\"Mary\", \"Zheng\", new BigDecimal(20)));\n\t\treports.add(buildGEmployee(\"Alex\", \"Zheng\", new BigDecimal(10)));\n\t\treports.add(buildGEmployee(\"Allen\", \"Zheng\", new BigDecimal(8)));\n\n\t\tdept.setEmployees(reports);\n\n\t\tBigDecimal budget = javaPayroll.caculateBudget(dept, BudgetType.YEARLY);\n\t\tassertTrue(budget.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\tprivate JEmployee buildJEmployee(String fname, String lname, BigDecimal money) {\n\t\tJEmployee mary = new JEmployee();\n\t\tmary.setFirstName(fname);\n\t\tmary.setLastName(lname);\n\t\tmary.setHourlyRate(money);\n\t\treturn mary;\n\t}\n\n\tprivate GEmployee buildGEmployee(String fname, String lname, BigDecimal money) {\n\t\tGEmployee mary = new GEmployee();\n\t\tmary.setFirstName(fname);\n\t\tmary.setLastName(lname);\n\t\tmary.setHourlyRate(money);\n\t\treturn mary;\n\t}\n\n}\n<\/pre>\n<\/a>4.3 Groovy Classes<\/h3>\nGroovy was introduced to ease the Java syntax’s complexity. The @Canonical<\/a><\/code> annotation assists Groovy developers to write shorter code. In this step, we will create three Groovy classes to implement the Payroll<\/code> interface.<\/p>\nDefine a department class which contains a list of employees. It’s much shorter and cleaner comparing to the Java class created in step 4.2<\/a>.<\/p>\nGDepartment.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model\n\nimport groovy.transform.*\n\n@Canonical\nclass GDepartment {\n\tint id\t\n\tList employees\n\n}\n<\/pre>\nDefine an employee class which contains the employee’s first name, last name, and hourly pay rate.<\/p>\n
GEmployee.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model\n\nimport groovy.transform.*\n\n@Canonical\nclass GEmployee {\n\tString firstName\n\tString lastName\n\tint id\n\tBigDecimal hourlyRate\n\t\n\tpublic BigDecimal caculatePay(BigDecimal hours) {\n\t\thourlyRate.multiply(hours)\n\t}\n}\n<\/pre>\nImplement the Payroll<\/code> interface’s two methods to calculate a given department’s budget.<\/p>\nWe can use Spring @Component<\/code> annotation to name it groovyPayroll<\/code> as a Spring bean. We also add time tracking to calculate the performance time.<\/p>\nGPayrollImpl.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.component\n\nimport java.time.Duration\nimport java.util.ArrayList\nimport java.util.List\n\nimport org.springframework.stereotype.Component\n\nimport groovy.time.TimeCategory\nimport groovy.time.TimeDuration\nimport jcg.zheng.demo.groovyspring.model.BudgetType\nimport jcg.zheng.demo.groovyspring.model.GDepartment\nimport jcg.zheng.demo.groovyspring.model.JDepartment\nimport jcg.zheng.demo.groovyspring.service.Payroll\n\n@Component(\"groovyPayroll\")\nclass GPayrollImpl implements Payroll{\n\n\t@Override\n\tpublic BigDecimal caculateBudget(JDepartment department, BudgetType type) {\n\t\tdef timeStart = new Date()\n\t\tList values = new ArrayList()\n\n\t\tdepartment.getEmployees().each { \n\t\t\tvalues.add(it.caculatePay(type.workingHours()))}\n\n\t\tdef timeStop = new Date()\n\t\tTimeDuration duration = TimeCategory.minus(timeStop, timeStart)\n\t\tprintln \"Groovy caculateBudget for JDepartment took \" + duration\n\n\t\tvalues.sum();\n\t}\n\n\t@Override\n\tpublic BigDecimal caculateBudget(GDepartment department, BudgetType type) {\n\t\tdef timeStart = new Date()\n\t\tList values = new ArrayList()\n\n\t\tdepartment.getEmployees().each {\n\t\t\tvalues.add(it.caculatePay(type.workingHours()))}\n\n\t\tdef timeStop = new Date()\n\t\tTimeDuration duration = TimeCategory.minus(timeStop, timeStart)\n\t\tprintln \"Groovy caculateBudget for GDepartment took \" + duration\n\t\tvalues.sum();\n\t}\n}\n<\/pre>\nCreate a Junit test class for GPayrollImp<\/code>. We use Spring @Autowired<\/code> annotation along with @Qualifier<\/code> to find the Groovy Payroll<\/code> bean.<\/p>\nGPayrollImpTest.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.component\n\nimport static org.junit.Assert.assertTrue\n\nimport org.junit.Test\nimport org.junit.runner.RunWith\nimport org.springframework.beans.factory.annotation.Autowired\nimport org.springframework.beans.factory.annotation.Qualifier\nimport org.springframework.boot.test.context.SpringBootTest\nimport org.springframework.test.context.junit4.SpringRunner\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType\nimport jcg.zheng.demo.groovyspring.model.GDepartment\nimport jcg.zheng.demo.groovyspring.model.GEmployee\nimport jcg.zheng.demo.groovyspring.model.JDepartment\nimport jcg.zheng.demo.groovyspring.model.JEmployee\nimport jcg.zheng.demo.groovyspring.service.Payroll\n\n@RunWith(SpringRunner.class)\n@SpringBootTest\nclass GroovyPayrollTest {\n\n\t@Autowired\n\t@Qualifier(\"groovyPayroll\")\n\tprivate Payroll groovyPayroll\n\n\t@Test\n\tpublic void test_GroovyPayroll_caculateBudget_for_GDepartment_yearly() {\n\t\tGDepartment department = new GDepartment()\n\n\t\tList reports = [\n\t\t\tnew GEmployee(firstName:\"Mary\", lastName:\"Zheng\", hourlyRate:new BigDecimal(20)),\n\t\t\tnew GEmployee(firstName:\"Alex\", lastName:\"Zheng\", hourlyRate:new BigDecimal(10)),\n\t\t\tnew GEmployee(firstName:\"Allen\", lastName:\"Zheng\", hourlyRate:new BigDecimal(8))\n\t\t]\n\n\t\tdepartment.setEmployees(reports);\n\n\t\tdef ret = groovyPayroll.caculateBudget(department, BudgetType.YEARLY)\n\t\tassertTrue(ret.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\t@Test\n\tpublic void test_GroovyPayroll_caculateBudget_for_JDepartment_yearly() {\n\t\tJDepartment department = new JDepartment()\n\n\t\tList reports = [\n\t\t\tnew JEmployee(firstName:\"Mary\", lastName:\"Zheng\", hourlyRate:new BigDecimal(20)),\n\t\t\tnew JEmployee(firstName:\"Alex\", lastName:\"Zheng\", hourlyRate:new BigDecimal(10)),\n\t\t\tnew JEmployee(firstName:\"Allen\", lastName:\"Zheng\", hourlyRate:new BigDecimal(8))\n\t\t]\n\n\t\tdepartment.setEmployees(reports);\n\n\t\tdef ret = groovyPayroll.caculateBudget(department, BudgetType.YEARLY)\n\t\tassertTrue(ret.compareTo(new BigDecimal(1520)) == 0);\n\t}\n}\n<\/pre>\n<\/a>5. Demo Java vs Groovy<\/h2>\nExecute mvn install<\/code> to build and run JPayrollImpTest<\/code> and GPayrollImpTest<\/code> and see the output below.<\/p>\nJPayrollImpTest output<\/em><\/span><\/p>\n2018-03-28 21:16:58.299 INFO 10460 --- [ main] j.z.d.g.service.impl.JPayrollImpTest : Started JPayrollImpTest in 8.053 seconds (JVM running for 9.671)\nJava caculateBudget for GDepartment took PT0.039S\nJava caculateBudget for JDepartment took PT0.003S\n<\/pre>\nGPayrollImpTest output<\/em><\/span><\/p>\n2018-03-28 21:18:37.369 INFO 7588 --- [ main] j.z.d.g.component.GroovyPayrollTest : Started GroovyPayrollTest in 5.96 seconds (JVM running for 7.935)\nGroovy caculateBudget for GDepartment took 0.036 seconds\nGroovy caculateBudget for JDepartment took 0.007 seconds\n<\/pre>\nTesting output shows that the Java implementation of the payroll service with the Java POJO class is the fastest of all four tests.<\/p>\n
<\/a>6. Spring Framework and Groovy<\/h2>\nIn this step, I will demonstrate how to invoke a Rest service and parse the results in Groovy.<\/p>\n
<\/a>6.1 Spring Properties<\/h3>\nThe Rest service is a public service which gets all the country’s information and gets state’s information for given country.<\/p>\n
Add the service host name and logging level in the Spring properties file.<\/p>\n
application.properties<\/em><\/span><\/p>\nAddressService.HostUrl=http:\/\/services.groupkt.com\n\nlogging.level.org.springframework=INFO\nlogging.level.jcg.zheng.demo=DEBUG<\/pre>\n<\/a>6.2 POGOs<\/h3>\nOpen browser and go to http:\/\/services.groupkt.com\/country\/get\/all<\/a> get all the country’s information. Go to http:\/\/services.groupkt.com\/state\/get\/USA\/all<\/a> to get all the state’s information for USA. Both services return a Json<\/code> object which contains a List<\/code> of String<\/code> messages and List of countries or states.<\/p>\nWe will create four POGOs to match the Rest service results. Then use JsonSlurper<\/code> to parse the results to the expected data type.<\/p>\nGCountry<\/code> class contains name<\/code>, alpha2_code<\/code>, and alpha3_code<\/code>.<\/p>\nGCountry.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport groovy.transform.*\n\n@Canonical\nclass GCountry {\n\n\tString name\n\tString alpha2_code\n\tString alpha3_code\n}\n<\/pre>\nGState<\/code> class contains name<\/code>, abbr<\/code>, and capital<\/code>, etc.<\/p>\nGState.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport groovy.transform.*\n\n@Canonical\nclass GState {\n\tLong id\n\tString country\n\tString name\n\tString abbr\n\tString area\n\tString capital\n\tString largest_city\n}\n<\/pre>\nGResponse<\/code> class contains messages<\/code> and result<\/code>.<\/p>\nGResponse.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\nimport groovy.transform.*\n\n@Canonical\nclass GResponse {\n\tList<String> messages\n\n\tList<Object> result\n}\n<\/pre>\nGResponseWrapper<\/code> class contains RestResponse<\/code>.[ulp id=’7POIYxRf1FUtPpmL’ name=’Spring Framework Cookbook Inline’]<\/p>\nGResponseWrapper.groovy<\/em><\/span><\/p>\npackage jcg.zheng.demo.groovyspring.model;\n\nimport groovy.json.internal.LazyMap\nimport groovy.transform.*\n@Canonical\nclass GResponseWrapper {\n\tGResponse RestResponse\n}\n<\/pre>\n<\/a>6.3 Address Service<\/h3>\nCreate an address service and annotate it with @Component<\/code>. It invokes a REST API service to get all the country’s information. The results is cached into the memory with the @Memoized<\/a><\/code> annotation.<\/p>\nAddressService<\/code> class contains two methods: getCountries<\/code> and getStates<\/code>.<\/p>\n
- \n
- 3.1. Groovy Dependency<\/a><\/dt>\n
- 3.2 Groovy Folders<\/a><\/dt>\n
- 3.3 Groovy Spring Application<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 4. Java and Groovy<\/a><\/dt>\n
- \n
- \n
- 4.1 Payroll Interface<\/a><\/dt>\n
- 4.2 Java Classes<\/a><\/dt>\n
- 4.3 Groovy Classes<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 5. Demo Java vs Groovy<\/a><\/dt>\n
- 6. Spring and Groovy<\/a><\/dt>\n
- \n
- \n
- 6.1 Spring Properties<\/a><\/dt>\n
- 6.2 POGOs<\/a><\/dt>\n
- 6.3 Address Service<\/a><\/dt>\n
- 6.4 Groovy Spring Application<\/a><\/dt>\n<\/dl>\n<\/dd>\n
- 7. Demo Spring Groovy Application<\/a><\/dt>\n
- 8. Spring Groovy – Summary<\/a><\/dt>\n
- 9. Reference<\/a><\/dt>\n
- 10. Download the Source Code<\/a><\/dt>\n<\/dl>\n<\/div>\n
<\/a>1. Introduction<\/h2>\n
Apache Groovy<\/a> (Groovy) is an object-oriented dynamic programming language for the Java platform. It is dynamically compiled to the Java Virtual Machine (JVM) bytecode, and inter-operates with other Java source codes and libraries. Groovy is written in Java. The first version 1.0 was released in 2007 to help developers to write a simple, elegant source code instead of the complicated Java code.<\/p>\n
Spring Framework<\/a> (Spring) is a Java application framework that provides many useful services for building applications. Spring 1.0 was released in 2004. Spring has supported Groovy fully since version 4 in 2013.<\/p>\n
Spring boot<\/a> defines a list of starter projects which each project includes a set of default component dependencies and automatic configuration of components.<\/p>\n
In this example, I will create a Spring boot application which utilizes Spring’s features in Groovy.<\/p>\n
<\/a>2. Technologies Used<\/h2>\n
The example code in this article was built and run using:<\/p>\n
- \n
- Java 1.8.101 (1.8.x will do fine)<\/li>\n
- Maven 3.3.9 (3.3.x will do fine)<\/li>\n
- Eclipse Mars (Any Java IDE would work)<\/li>\n
- Spring boot 1.5.10.RELEASE<\/li>\n
- Groovy 2.4<\/li>\n<\/ul>\n
<\/a>3. Spring-boot Application<\/h2>\n
The easiest way to generate a Spring-boot application is via the Spring starter tool<\/a>. Please check my other article here<\/a> for more details. A maven project will be generated and downloaded to your workstation. Import it into your Eclipse work space. You should have no errors on building it and running it as a Spring Boot Application.<\/p>\n
We will change it to a Groovy spring application with three steps:<\/p>\n
- \n
- Add a Groovy dependency in the
pom.xml<\/code><\/li>\n- Add a Groovy source folder<\/li>\n
- Change Spring Application to a Groovy class<\/li>\n<\/ol>\n
<\/a>3.1 Groovy Dependency<\/h3>\n
The generated
pom.xml<\/code> does not include the Groovy library. We will add it as a dependency.<\/p>\npom.xml<\/em><\/span><\/p>\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<project xmlns=\"http:\/\/maven.apache.org\/POM\/4.0.0\" xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\n\txsi:schemaLocation=\"http:\/\/maven.apache.org\/POM\/4.0.0 http:\/\/maven.apache.org\/xsd\/maven-4.0.0.xsd\">\n\t<modelVersion>4.0.0<\/modelVersion>\n\n\t<groupId>jcg.zheng.demo<\/groupId>\n\t<artifactId>groovy-spring<\/artifactId>\n\t<version>0.0.1-SNAPSHOT<\/version>\n\t<packaging>jar<\/packaging>\n\n\t<name>groovy-spring<\/name>\n\t<description>Demo project for Spring Boot<\/description>\n\n\t<parent>\n\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t<artifactId>spring-boot-starter-parent<\/artifactId>\n\t\t<version>1.5.10.RELEASE<\/version>\n\t\t<relativePath\/> <!-- lookup parent from repository -->\n\t<\/parent>\n\n\t<properties>\n\t\t<project.build.sourceEncoding>UTF-8<\/project.build.sourceEncoding>\n\t\t<project.reporting.outputEncoding>UTF-8<\/project.reporting.outputEncoding>\n\t\t<java.version>1.8<\/java.version>\n\t<\/properties>\n\n\t<dependencies>\n\t\t<dependency>\n\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t<artifactId>spring-boot-starter-web<\/artifactId>\n\t\t<\/dependency>\n\n\t\t<dependency>\n\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t<artifactId>spring-boot-starter-test<\/artifactId>\n\t\t\t<scope>test<\/scope>\n\t\t<\/dependency>\n\t\t<dependency>\n\t\t\t<groupId>org.codehaus.groovy<\/groupId>\n\t\t\t<artifactId>groovy-all<\/artifactId>\n\t\t<\/dependency>\n\t<\/dependencies>\n\n\t<build>\n\t\t<plugins>\n\t\t\t<plugin>\n\t\t\t\t<groupId>org.springframework.boot<\/groupId>\n\t\t\t\t<artifactId>spring-boot-maven-plugin<\/artifactId>\n\t\t\t<\/plugin>\n\t\t<\/plugins>\n\t<\/build>\n\n<\/project>\n<\/pre>\n
<\/a>3.2 Groovy Folders<\/h3>\n
The generated project has a
Java<\/code> source folder. We will add two folders:src\/main\/groovy<\/code> andsrc\/test\/groovy<\/code>. Then we will include them as the build resources.<\/p>\n\n<\/a>Figure 1 Project Structure<\/figcaption><\/figure>\n<\/div>\n <\/a>3.3 Spring Framework Application in Groovy<\/h3>\n
The generated
GroovySpringApplication<\/code> is aJava<\/code> class. We will change it to aGroovy<\/code> class and move it under thesrc\/main\/groovy<\/code> folder.<\/p>\nYou can execute
mvn install<\/code> to build it and then run it as a Spring boot application.<\/p>\n<\/a>4. Java and Groovy<\/h2>\n
We will define
Payroll<\/code> interface and implement it with bothJava<\/code> andGroovy<\/code> and compare their performance.<\/p>\n<\/a>4.1 Payroll Interface<\/h3>\n
Define
Payroll<\/code> interface to calculate the department’s budget based on the time period.<\/p>\nPayroll.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.service;\n\nimport java.math.BigDecimal;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\n\npublic interface Payroll {\n\n\tBigDecimal caculateBudget(JDepartment department, BudgetType type);\n\tBigDecimal caculateBudget(GDepartment department, BudgetType type);\n\n}\n<\/pre>\nNote<\/strong>: It defines
caculateBudget<\/code> method for both Java Department and Groovy Department. We use it to demonstrate the method’s performance.<\/p>\nDefine
BudgetType<\/code>enum<\/code> for four time periods.<\/p>\nBudgetType.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport java.math.BigDecimal;\n\npublic enum BudgetType {\n\n\tYEARLY, QUARTERLY, MONTHLY, WEEKLY;\n\n\tpublic BigDecimal workingHours() {\n\t\tBigDecimal workingHours = new BigDecimal(0);\n\t\tswitch (this) {\n\t\tcase YEARLY:\n\t\t\tworkingHours = new BigDecimal(2080);\n\t\tcase QUARTERLY:\n\t\t\tworkingHours = new BigDecimal(520);\n\t\tcase MONTHLY:\n\t\t\tworkingHours = new BigDecimal(173.34);\n\t\tcase WEEKLY:\n\t\t\tworkingHours = new BigDecimal(40);\n\t\t}\n\t\treturn workingHours;\n\t}\n\n}\n<\/pre>\n<\/a>4.2 Java Classes<\/h3>\n
In this step, we will create three Java classes to implement the
Payroll<\/code> interface.<\/p>\nDefine a department class which contains a list of employees.<\/p>\n
JDepartment.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport java.util.List;\n\npublic class JDepartment {\n\tprivate int id;\n\n\tprivate List employees;\n\n\tpublic List getEmployees() {\n\t\treturn employees;\n\t}\n\n\tpublic void setEmployees(List employees) {\n\t\tthis.employees = employees;\n\t}\n\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\n\tpublic void setId(int id) {\n\t\tthis.id = id;\n\t}\n}\n<\/pre>\nDefine an employee class which contains the employee’s first name, last name, and hourly pay rate.<\/p>\n
JEmployee.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport java.math.BigDecimal;\n\npublic class JEmployee {\n\tpublic JEmployee() {\n\t\tsuper();\n\t}\n\n\tprivate String firstName;\n\tprivate String lastName;\n\tprivate int id;\n\tprivate BigDecimal hourlyRate;\n\n\tpublic BigDecimal caculatePay(BigDecimal hours) {\n\t\treturn hourlyRate.multiply(hours);\n\t}\n\n\tpublic String getFirstName() {\n\t\treturn firstName;\n\t}\n\n\tpublic void setFirstName(String firstName) {\n\t\tthis.firstName = firstName;\n\t}\n\n\tpublic String getLastName() {\n\t\treturn lastName;\n\t}\n\n\tpublic void setLastName(String lastName) {\n\t\tthis.lastName = lastName;\n\t}\n\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\n\tpublic void setId(int id) {\n\t\tthis.id = id;\n\t}\n\n\tpublic BigDecimal getHourlyRate() {\n\t\treturn hourlyRate;\n\t}\n\n\tpublic void setHourlyRate(BigDecimal hourlyRate) {\n\t\tthis.hourlyRate = hourlyRate;\n\t}\n\n}\n<\/pre>\nImplement the
Payroll<\/code> interface’s two methods to calculate a given department’s budget.<\/p>\nJPayrollImpl.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.service.impl;\n\nimport java.math.BigDecimal;\nimport java.time.Duration;\nimport java.time.Instant;\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.stereotype.Component;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\nimport jcg.zheng.demo.groovyspring.service.Payroll;\n\n@Component(\"javaPayroll\")\npublic class JPayrollImp implements Payroll {\n\n\t@Override\n\tpublic BigDecimal caculateBudget(JDepartment department, BudgetType type) {\n\t\tInstant start = Instant.now();\n\n\t\tList values = new ArrayList();\n\t\tdepartment.getEmployees().forEach(emp -> values.add(emp.caculatePay(type.workingHours())));\n\n\t\tBigDecimal result = values.stream().reduce(BigDecimal::add).get();\n\n\t\tInstant end = Instant.now();\n\n\t\tSystem.out.println(\"Java caculateBudget for JDepartment took \" + Duration.between(start, end));\n\n\t\treturn result;\n\t}\n\n\t@Override\n\tpublic BigDecimal caculateBudget(GDepartment department, BudgetType type) {\n\t\tInstant start = Instant.now();\n\n\t\tList values = new ArrayList();\n\t\tdepartment.getEmployees().forEach(emp -> values.add(emp.caculatePay(type.workingHours())));\n\n\t\tBigDecimal result = values.stream().reduce(BigDecimal::add).get();\n\n\t\tInstant end = Instant.now();\n\n\t\tSystem.out.println(\"Java caculateBudget for GDepartment took \" + Duration.between(start, end));\n\n\t\treturn result;\n\t}\n\n}\n<\/pre>\nCreate a Junit test class for
JPayrollImp<\/code>.<\/div> <\/div><\/p>\nJPayrollImpTest.java<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.service.impl;\n\nimport static org.junit.Assert.*;\n\nimport java.math.BigDecimal;\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.junit.Test;\nimport org.junit.runner.RunWith;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.beans.factory.annotation.Qualifier;\nimport org.springframework.boot.test.context.SpringBootTest;\nimport org.springframework.test.context.junit4.SpringRunner;\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType;\nimport jcg.zheng.demo.groovyspring.model.GDepartment;\nimport jcg.zheng.demo.groovyspring.model.GEmployee;\nimport jcg.zheng.demo.groovyspring.model.JDepartment;\nimport jcg.zheng.demo.groovyspring.model.JEmployee;\nimport jcg.zheng.demo.groovyspring.service.Payroll;\n\n@RunWith(SpringRunner.class)\n@SpringBootTest\npublic class JPayrollImpTest {\n\n\t@Autowired\n\t@Qualifier(\"javaPayroll\")\n\tprivate Payroll javaPayroll;\n\n\t@Test\n\tpublic void test_JavaPayroll_caculateBudget_for_JDepartment_yearly() {\n\t\tJDepartment dept = new JDepartment();\n\n\t\tList reports = new ArrayList();\n\t\treports.add(buildJEmployee(\"Mary\", \"Zheng\", new BigDecimal(20)));\n\t\treports.add(buildJEmployee(\"Alex\", \"Zheng\", new BigDecimal(10)));\n\t\treports.add(buildJEmployee(\"Allen\", \"Zheng\", new BigDecimal(8)));\n\n\t\tdept.setEmployees(reports);\n\n\t\tBigDecimal budget = javaPayroll.caculateBudget(dept, BudgetType.YEARLY);\n\t\tassertTrue(budget.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\t@Test\n\tpublic void test_JavaPayroll_caculateBudget_for_GDepartment_yearly() {\n\t\tGDepartment dept = new GDepartment();\n\n\t\tList reports = new ArrayList();\n\t\treports.add(buildGEmployee(\"Mary\", \"Zheng\", new BigDecimal(20)));\n\t\treports.add(buildGEmployee(\"Alex\", \"Zheng\", new BigDecimal(10)));\n\t\treports.add(buildGEmployee(\"Allen\", \"Zheng\", new BigDecimal(8)));\n\n\t\tdept.setEmployees(reports);\n\n\t\tBigDecimal budget = javaPayroll.caculateBudget(dept, BudgetType.YEARLY);\n\t\tassertTrue(budget.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\tprivate JEmployee buildJEmployee(String fname, String lname, BigDecimal money) {\n\t\tJEmployee mary = new JEmployee();\n\t\tmary.setFirstName(fname);\n\t\tmary.setLastName(lname);\n\t\tmary.setHourlyRate(money);\n\t\treturn mary;\n\t}\n\n\tprivate GEmployee buildGEmployee(String fname, String lname, BigDecimal money) {\n\t\tGEmployee mary = new GEmployee();\n\t\tmary.setFirstName(fname);\n\t\tmary.setLastName(lname);\n\t\tmary.setHourlyRate(money);\n\t\treturn mary;\n\t}\n\n}\n<\/pre>\n<\/a>4.3 Groovy Classes<\/h3>\n
Groovy was introduced to ease the Java syntax’s complexity. The
@Canonical<\/a><\/code> annotation assists Groovy developers to write shorter code. In this step, we will create three Groovy classes to implement thePayroll<\/code> interface.<\/p>\nDefine a department class which contains a list of employees. It’s much shorter and cleaner comparing to the Java class created in step 4.2<\/a>.<\/p>\n
GDepartment.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model\n\nimport groovy.transform.*\n\n@Canonical\nclass GDepartment {\n\tint id\t\n\tList employees\n\n}\n<\/pre>\nDefine an employee class which contains the employee’s first name, last name, and hourly pay rate.<\/p>\n
GEmployee.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model\n\nimport groovy.transform.*\n\n@Canonical\nclass GEmployee {\n\tString firstName\n\tString lastName\n\tint id\n\tBigDecimal hourlyRate\n\t\n\tpublic BigDecimal caculatePay(BigDecimal hours) {\n\t\thourlyRate.multiply(hours)\n\t}\n}\n<\/pre>\nImplement the
Payroll<\/code> interface’s two methods to calculate a given department’s budget.<\/p>\nWe can use Spring
@Component<\/code> annotation to name itgroovyPayroll<\/code> as a Spring bean. We also add time tracking to calculate the performance time.<\/p>\nGPayrollImpl.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.component\n\nimport java.time.Duration\nimport java.util.ArrayList\nimport java.util.List\n\nimport org.springframework.stereotype.Component\n\nimport groovy.time.TimeCategory\nimport groovy.time.TimeDuration\nimport jcg.zheng.demo.groovyspring.model.BudgetType\nimport jcg.zheng.demo.groovyspring.model.GDepartment\nimport jcg.zheng.demo.groovyspring.model.JDepartment\nimport jcg.zheng.demo.groovyspring.service.Payroll\n\n@Component(\"groovyPayroll\")\nclass GPayrollImpl implements Payroll{\n\n\t@Override\n\tpublic BigDecimal caculateBudget(JDepartment department, BudgetType type) {\n\t\tdef timeStart = new Date()\n\t\tList values = new ArrayList()\n\n\t\tdepartment.getEmployees().each { \n\t\t\tvalues.add(it.caculatePay(type.workingHours()))}\n\n\t\tdef timeStop = new Date()\n\t\tTimeDuration duration = TimeCategory.minus(timeStop, timeStart)\n\t\tprintln \"Groovy caculateBudget for JDepartment took \" + duration\n\n\t\tvalues.sum();\n\t}\n\n\t@Override\n\tpublic BigDecimal caculateBudget(GDepartment department, BudgetType type) {\n\t\tdef timeStart = new Date()\n\t\tList values = new ArrayList()\n\n\t\tdepartment.getEmployees().each {\n\t\t\tvalues.add(it.caculatePay(type.workingHours()))}\n\n\t\tdef timeStop = new Date()\n\t\tTimeDuration duration = TimeCategory.minus(timeStop, timeStart)\n\t\tprintln \"Groovy caculateBudget for GDepartment took \" + duration\n\t\tvalues.sum();\n\t}\n}\n<\/pre>\nCreate a Junit test class for
GPayrollImp<\/code>. We use Spring@Autowired<\/code> annotation along with@Qualifier<\/code> to find the GroovyPayroll<\/code> bean.<\/p>\nGPayrollImpTest.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.component\n\nimport static org.junit.Assert.assertTrue\n\nimport org.junit.Test\nimport org.junit.runner.RunWith\nimport org.springframework.beans.factory.annotation.Autowired\nimport org.springframework.beans.factory.annotation.Qualifier\nimport org.springframework.boot.test.context.SpringBootTest\nimport org.springframework.test.context.junit4.SpringRunner\n\nimport jcg.zheng.demo.groovyspring.model.BudgetType\nimport jcg.zheng.demo.groovyspring.model.GDepartment\nimport jcg.zheng.demo.groovyspring.model.GEmployee\nimport jcg.zheng.demo.groovyspring.model.JDepartment\nimport jcg.zheng.demo.groovyspring.model.JEmployee\nimport jcg.zheng.demo.groovyspring.service.Payroll\n\n@RunWith(SpringRunner.class)\n@SpringBootTest\nclass GroovyPayrollTest {\n\n\t@Autowired\n\t@Qualifier(\"groovyPayroll\")\n\tprivate Payroll groovyPayroll\n\n\t@Test\n\tpublic void test_GroovyPayroll_caculateBudget_for_GDepartment_yearly() {\n\t\tGDepartment department = new GDepartment()\n\n\t\tList reports = [\n\t\t\tnew GEmployee(firstName:\"Mary\", lastName:\"Zheng\", hourlyRate:new BigDecimal(20)),\n\t\t\tnew GEmployee(firstName:\"Alex\", lastName:\"Zheng\", hourlyRate:new BigDecimal(10)),\n\t\t\tnew GEmployee(firstName:\"Allen\", lastName:\"Zheng\", hourlyRate:new BigDecimal(8))\n\t\t]\n\n\t\tdepartment.setEmployees(reports);\n\n\t\tdef ret = groovyPayroll.caculateBudget(department, BudgetType.YEARLY)\n\t\tassertTrue(ret.compareTo(new BigDecimal(1520)) == 0);\n\t}\n\n\t@Test\n\tpublic void test_GroovyPayroll_caculateBudget_for_JDepartment_yearly() {\n\t\tJDepartment department = new JDepartment()\n\n\t\tList reports = [\n\t\t\tnew JEmployee(firstName:\"Mary\", lastName:\"Zheng\", hourlyRate:new BigDecimal(20)),\n\t\t\tnew JEmployee(firstName:\"Alex\", lastName:\"Zheng\", hourlyRate:new BigDecimal(10)),\n\t\t\tnew JEmployee(firstName:\"Allen\", lastName:\"Zheng\", hourlyRate:new BigDecimal(8))\n\t\t]\n\n\t\tdepartment.setEmployees(reports);\n\n\t\tdef ret = groovyPayroll.caculateBudget(department, BudgetType.YEARLY)\n\t\tassertTrue(ret.compareTo(new BigDecimal(1520)) == 0);\n\t}\n}\n<\/pre>\n<\/a>5. Demo Java vs Groovy<\/h2>\n
Execute
mvn install<\/code> to build and runJPayrollImpTest<\/code> andGPayrollImpTest<\/code> and see the output below.<\/p>\nJPayrollImpTest output<\/em><\/span><\/p>\n
2018-03-28 21:16:58.299 INFO 10460 --- [ main] j.z.d.g.service.impl.JPayrollImpTest : Started JPayrollImpTest in 8.053 seconds (JVM running for 9.671)\nJava caculateBudget for GDepartment took PT0.039S\nJava caculateBudget for JDepartment took PT0.003S\n<\/pre>\n
GPayrollImpTest output<\/em><\/span><\/p>\n
2018-03-28 21:18:37.369 INFO 7588 --- [ main] j.z.d.g.component.GroovyPayrollTest : Started GroovyPayrollTest in 5.96 seconds (JVM running for 7.935)\nGroovy caculateBudget for GDepartment took 0.036 seconds\nGroovy caculateBudget for JDepartment took 0.007 seconds\n<\/pre>\n
Testing output shows that the Java implementation of the payroll service with the Java POJO class is the fastest of all four tests.<\/p>\n
<\/a>6. Spring Framework and Groovy<\/h2>\n
In this step, I will demonstrate how to invoke a Rest service and parse the results in Groovy.<\/p>\n
<\/a>6.1 Spring Properties<\/h3>\n
The Rest service is a public service which gets all the country’s information and gets state’s information for given country.<\/p>\n
Add the service host name and logging level in the Spring properties file.<\/p>\n
application.properties<\/em><\/span><\/p>\n
AddressService.HostUrl=http:\/\/services.groupkt.com\n\nlogging.level.org.springframework=INFO\nlogging.level.jcg.zheng.demo=DEBUG<\/pre>\n
<\/a>6.2 POGOs<\/h3>\n
Open browser and go to http:\/\/services.groupkt.com\/country\/get\/all<\/a> get all the country’s information. Go to http:\/\/services.groupkt.com\/state\/get\/USA\/all<\/a> to get all the state’s information for USA. Both services return a
Json<\/code> object which contains aList<\/code> ofString<\/code> messages and List of countries or states.<\/p>\nWe will create four POGOs to match the Rest service results. Then use
JsonSlurper<\/code> to parse the results to the expected data type.<\/p>\nGCountry<\/code> class containsname<\/code>,alpha2_code<\/code>, andalpha3_code<\/code>.<\/p>\nGCountry.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport groovy.transform.*\n\n@Canonical\nclass GCountry {\n\n\tString name\n\tString alpha2_code\n\tString alpha3_code\n}\n<\/pre>\nGState<\/code> class containsname<\/code>,abbr<\/code>, andcapital<\/code>, etc.<\/p>\nGState.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport groovy.transform.*\n\n@Canonical\nclass GState {\n\tLong id\n\tString country\n\tString name\n\tString abbr\n\tString area\n\tString capital\n\tString largest_city\n}\n<\/pre>\nGResponse<\/code> class containsmessages<\/code> andresult<\/code>.<\/p>\nGResponse.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\nimport groovy.transform.*\n\n@Canonical\nclass GResponse {\n\tList<String> messages\n\n\tList<Object> result\n}\n<\/pre>\nGResponseWrapper<\/code> class containsRestResponse<\/code>.[ulp id=’7POIYxRf1FUtPpmL’ name=’Spring Framework Cookbook Inline’]<\/p>\nGResponseWrapper.groovy<\/em><\/span><\/p>\n
package jcg.zheng.demo.groovyspring.model;\n\nimport groovy.json.internal.LazyMap\nimport groovy.transform.*\n@Canonical\nclass GResponseWrapper {\n\tGResponse RestResponse\n}\n<\/pre>\n<\/a>6.3 Address Service<\/h3>\n
Create an address service and annotate it with
@Component<\/code>. It invokes a REST API service to get all the country’s information. The results is cached into the memory with the@Memoized<\/a><\/code> annotation.<\/p>\nAddressService<\/code> class contains two methods:getCountries<\/code> andgetStates<\/code>.<\/p>\n
- Add a Groovy dependency in the
- 6.2 POGOs<\/a><\/dt>\n
- 4.2 Java Classes<\/a><\/dt>\n
- 3.2 Groovy Folders<\/a><\/dt>\n