Jersey 客户端示例 – Jersey2 客户端 API · HowToDoInJava 中文系列教程

# Jersey 客户端示例 – Jersey2 客户端 API > 原文： [https://howtodoinjava.com/jersey/jersey-restful-client-examples/](https://howtodoinjava.com/jersey/jersey-restful-client-examples/) [**Jersey**](//howtodoinjava.com/jersey-jax-rs-tutorials/) 2 客户端 API 从专有的 Jersey 1.x 客户端 API 中得到启发。在此 **Jersey 客户端示例**中，我们将学习*构建客户端 API* 并调用不同的 REST 方法并使用 API 结果。 ```java Table of Contents 1\. Jersey Client Maven 2\. Jersey ClientBuilder 3\. HTTP GET - Collection/List of Entities 4\. HTTP GET - Single Entity 5\. HTTP POST 6\. HTTP PUT 7\. HTTP DELETE 8\. Model classes and Configuration files ``` ## 1\. Jersey 客户端 Maven 在`pom.xml`文件中添加 jersey 客户端 maven 依赖项。 ```java <dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-client</artifactId> <version>2.25.1</version> </dependency> ``` ## 2\. Jersey `ClientBuilder` **JAX-RS 客户端 API** 设计为允许流畅的编程模型。要创建 Jersey 客户端，请按照以下步骤操作： 1. 使用`ClientBuilder.newClient()`静态方法。 2. 在上面获得的客户端实例上使用`client.target()`方法。 3. 在第二步中获得的`WebTarget`实例上，使用`webTarget.request()`方法获取`Invocation.Builder`。 4. 执行`invocationBuilder.get()`，`put()`，`post()`或`delete()`方法以调用相应的 REST API。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees"); Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_XML); Response response = invocationBuilder.post(Entity.entity(emp, MediaType.APPLICATION_XML)); ``` 下面给出的示例将有助于我们更好地理解并为开发任务做好准备。我建议您浏览其他 Jersey 示例，例如[**文件上传示例**](//howtodoinjava.com/jersey/jersey-file-upload-example/)和[**文件下载示例**](//howtodoinjava.com/jersey/jax-rs-jersey-2-file-download-example-using-streamingoutput/)。 ## 3\. HTTP GET – 实体的集合/列表 #### REST API 这是用于检索系统中所有员工的 API 代码。 ```java @GET @Path("/employees") @Produces(MediaType.APPLICATION_XML) public Employees getAllEmployees() { Employees list = new Employees(); list.setEmployeeList(new ArrayList<Employee>()); list.getEmployeeList().add(new Employee(1, "Lokesh Gupta")); list.getEmployeeList().add(new Employee(2, "Alex Kolenchiskey")); list.getEmployeeList().add(new Employee(3, "David Kameron")); return list; } ``` #### Jersey 客户端代码此 RESTful 客户端代码将访问上述 API，并在控制台中打印响应。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees"); Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_XML); Response response = invocationBuilder.get(); Employees employees = response.readEntity(Employees.class); List<Employee> listOfEmployees = employees.getEmployeeList(); System.out.println(response.getStatus()); System.out.println(Arrays.toString( listOfEmployees.toArray(new Employee[listOfEmployees.size()]) )); Output: 200 [Employee [id=1, name=Lokesh Gupta], Employee [id=2, name=Alex Kolenchiskey], Employee [id=3, name=David Kameron]] ``` ## 4\. HTTP GET – 单一实体这是 API 代码，用于根据其 ID 检索单个员工。 ```java @GET @Path("/employees/{id}") @Produces(MediaType.APPLICATION_XML) public Response updateEmployeeById(@PathParam("id") Integer id) { if(id < 0){ return Response.noContent().build(); } Employee emp = new Employee(); emp.setId(id); emp.setName("Lokesh Gupta"); GenericEntity<Employee> entity = new GenericEntity<Employee>(emp, Employee.class); return Response.ok().entity(entity).build(); } ``` #### 客户端代码此 RESTful 客户端代码将访问上述 API，并在控制台中打印响应。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees").path("1"); Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_XML); Response response = invocationBuilder.get(); Employee employee = response.readEntity(Employee.class); System.out.println(response.getStatus()); System.out.println(employee); Output: 200 Employee [id=1, name=Lokesh Gupta] ``` ## 5\. HTTP POST 这是用于在集合中添加员工的 API 代码。 ```java @POST @Path("/employees") @Consumes(MediaType.APPLICATION_XML) @Produces(MediaType.APPLICATION_XML) public Response addEmployee( Employee e ) throws URISyntaxException { if(e == null){ return Response.status(400).entity("Please add employee details !!").build(); } if(e.getName() == null) { return Response.status(400).entity("Please provide the employee name !!").build(); } return Response.created(new URI("/rest/employees/"+e.getId())).build(); } ``` #### Jersey 客户端代码此 RESTful 客户端代码将访问上述 API，并在控制台中打印响应。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees"); Employee emp = new Employee(); emp.setId(1); emp.setName("David Feezor"); Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_XML); Response response = invocationBuilder.post(Entity.entity(emp, MediaType.APPLICATION_XML)); System.out.println(response.getStatus()); System.out.println(response.readEntity(String.class)); Output: 201 ``` ## 6\. HTTP PUT 这是 API 代码，用于通过其 ID 更新员工名称。 ```java @PUT @Path("/employees/{id}") @Consumes(MediaType.APPLICATION_XML) @Produces(MediaType.APPLICATION_XML) public Response updateEmployeeById(@PathParam("id") Integer id, Employee e) { Employee updatedEmployee = new Employee(); if(e.getName() == null) { return Response.status(400).entity("Please provide the employee name !!").build(); } updatedEmployee.setId(id); updatedEmployee.setName(e.getName()); return Response.ok().entity(updatedEmployee).build(); } ``` #### Jersey2 客户端代码此 RESTful 客户端代码将访问上述 API，并在控制台中打印响应。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees").path("1"); Employee emp = new Employee(); emp.setId(1); emp.setName("David Feezor"); Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_XML); Response response = invocationBuilder.put(Entity.entity(emp, MediaType.APPLICATION_XML)); Employee employee = response.readEntity(Employee.class); System.out.println(response.getStatus()); System.out.println(employee); Output: 200 Employee [id=1, name=David Feezor] ``` ## 7\. HTTP DELETE 这是用于通过 ID 从集合中删除员工的 API 代码。 ```java @DELETE @Path("/employees/{id}") public Response deleteEmployeeById(@PathParam("id") Integer id) { return Response.status(202).entity("Employee deleted successfully !!").build(); } ``` #### Jersey 客户端代码此 RESTful 客户端代码将访问上述 API，并在控制台中打印响应。 ```java Client client = ClientBuilder.newClient( new ClientConfig().register( LoggingFilter.class ) ); WebTarget webTarget = client.target("http://localhost:8080/JerseyDemos/rest").path("employees").path("1"); Invocation.Builder invocationBuilder = webTarget.request(); Response response = invocationBuilder.delete(); System.out.println(response.getStatus()); System.out.println(response.readEntity(String.class)); Output: 202 Employee deleted successfully !! ``` ## 8\. 模型类和配置文件下面列出了其他用于创建此 **Jersey2 客户端示例**的文件。 #### `Employees.java` ```java package com.howtodoinjava.jersey; import java.util.List; import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlRootElement; @XmlRootElement(name = "employeeList") @XmlAccessorType (XmlAccessType.FIELD) public class Employees { @XmlElement(name="employee") private List<Employee> employeeList; public List<Employee> getEmployeeList() { return employeeList; } public void setEmployeeList(List<Employee> employeeList) { this.employeeList = employeeList; } } ``` #### `Employee.java` ```java package com.howtodoinjava.jersey; import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlRootElement; @XmlRootElement(name = "employee") @XmlAccessorType (XmlAccessType.FIELD) public class Employee { private Integer id; private String name; public Employee() { } public Employee(Integer id, String name) { this.id = id; this.name = name; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return "Employee [id=" + id + ", name=" + name + "]"; } } ``` #### `pom.xml` ```java <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd; <modelVersion>4.0.0</modelVersion> <groupId>com.howtodoinjava.jersey</groupId> <artifactId>JerseyDemos</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <repositories> <repository> <id>maven2-repository.java.net</id> <name>Java.net Repository for Maven</name> <url>http://download.java.net/maven/2/</url> <layout>default</layout> </repository> </repositories> <properties> <jersey2.version>2.19</jersey2.version> <jaxrs.version>2.0.1</jaxrs.version> </properties> <dependencies>  <dependency> <groupId>javax.ws.rs</groupId> <artifactId>javax.ws.rs-api</artifactId> <version>${jaxrs.version}</version> </dependency>  <dependency> <groupId>org.glassfish.jersey.containers</groupId> <artifactId>jersey-container-servlet</artifactId> <version>${jersey2.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-server</artifactId> <version>${jersey2.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-client</artifactId> <version>${jersey2.version}</version> </dependency> <dependency> <groupId>org.glassfish.jersey.media</groupId> <artifactId>jersey-media-multipart</artifactId> <version>${jersey2.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.jaxrs</groupId> <artifactId>jackson-jaxrs-json-provider</artifactId> <version>2.4.1</version> </dependency> </dependencies> <build> <finalName>JerseyDemos</finalName> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.7</source> <target>1.7</target> </configuration> </plugin> </plugins> </build> </project> ``` #### `web.xml` ```java <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>jersey-serlvet</servlet-name> <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class> <init-param> <param-name>jersey.config.server.provider.packages</param-name> <param-value>com.howtodoinjava.jersey</param-value> </init-param> <init-param> <param-name>jersey.config.server.provider.classnames</param-name> <param-value>org.glassfish.jersey.filter.LoggingFilter</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>jersey-serlvet</servlet-name> <url-pattern>/rest/*</url-pattern> </servlet-mapping> </web-app> ``` 在下面将您的问题和评论发送给我。学习愉快！参考： [Jersey 客户端 Java 文档](https://jersey.java.net/documentation/latest/client.html)