Restlet - 使用Restlet自身组件Application/Component的开发实例

1、示例说明
版本：Restlet版本为2.1.0。 相关：实例是使用Restlet自身的Application和Component组件。
2、创建Java Web工程，添加相关Jar。实例中工程名为RestletService


3、创建Model，示例为Student

publicclassStudent {
privateInteger id;
privateString name;
privateInteger sex;
privateInteger age;
publicStudent() {
}
/**setter/getter**/
}

4、[b]创建[b]BusinessObject类，示例虚拟了一个数据库和相应的一些操作[/b][/b]

publicclassStudentBO {
privatestaticMap<Integer, Student> students = newHashMap<Integer, Student>();
// next Id
privatestaticintnextId = 5;
static{
students.put(1, newStudent(1, "Michael", 1, 18));
students.put(2, newStudent(2, "Anthony", 1, 22));
students.put(3, newStudent(3, "Isabella", 0, 19));
students.put(4, newStudent(4, "Aiden", 1, 20));
}
publicStudent getStudent(Integer id) {
returnstudents.get(id);
}
publicList<Student> getStudentAll() {
returnnewArrayList<Student>(students.values());
}
publicInteger saveOrUpdateStudent(Student student) {
if(student.getId() == null) {
student.setId(nextId++);
}
students.put(student.getId(), student);
returnstudent.getId();
}
publicInteger removeStudent(Integer id) {
students.remove(id);
returnid;
}
}

5、创建对应的Resource类，具体看注释
(1)、StudentResource类，主要针对单一查询，修改和删除操作

publicclassStudentResource extendsServerResource {
privateintid;
privateStudentBO studentService = newStudentBO();
/**
* 用来获取传递过来的studentId占位符的值
*/
@Override
protectedvoiddoInit() throwsResourceException {
id = Integer.valueOf((String) getRequestAttributes().get("studentId"));
}
@Get("json")
publicStudent getStudent(){
returnstudentService.getStudent(id);
}
@Delete
publicInteger deleteStudent() {
returnstudentService.removeStudent(id);
}
@Put("json")
publicInteger updateStudent(Student student){
student.setId(id);
returnstudentService.saveOrUpdateStudent(student);
}
/*
* 第二种传入参数和返回值的方式
* @Put
* public Representation put(Representation entity) throws ResourceException {
*    //entity这样一个对象将会把客户端传进来参数保存在其中，通过如下方式可以获取参数值
*    Form form = new Form(entity);
*    Student student = new Student();
*    String name = form.getFirstValue("name");
*    int sex = Integer.parseInt(form.getFirstValue("sex"));
*    int age = Integer.parseInt(form.getFirstValue("age"));
*    student.setName(name);
*    student.setSex(sex);
*    student.setAge(age);
*    student.setId(id);
*    studentService.saveOrUpdateStudent(student)；
*    //实例返回的是String类型的扩展，当然你也可以返回JsonRepresentation这样一个扩展
*    return new StringRepresentation(student.toString()); //为了更好的说明返回整个对象
*
* }
*/
}

(2)、StudentListResource类，主要针对多返回查询和新增操作

publicclassStudentListResource extendsServerResource {
privateStudentBO studentService = newStudentBO();
@Get("json")
publicList<Student> get(Representation entity) {
List<Student> studentList = studentService.getStudentAll();
returnstudentList;
}
@Post("json")
publicInteger saveStudent(Student student) {
returnstudentService.saveOrUpdateStudent(student);
}
}

6、扩展org.restlet.Application类

publicclassStudentApplication extendsApplication {
/**
* 重写createInboundRoot通过attach方法绑定资源类，并且制定了访问路径
*/
@Override
publicRestlet createInboundRoot() {
Router router = newRouter(getContext());
router.attach("/student/{studentId}", StudentResource.class);
router.attach("/student", StudentListResource.class);
returnrouter;
}
}

7、配置web.xml

<context-param>
<param-name>org.restlet.application</param-name>
<!-- 自定义org.restlet.Application扩展类  -->
<param-value>com.rc.rl.StudentApplication</param-value>
</context-param>
<servlet>
<servlet-name>RestletServlet</servlet-name>
<servlet-class>org.restlet.ext.servlet.ServerServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RestletServlet</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>

8、Test客户端

/**
*客户端使用了Junit4
*/
publicclassStudentClient {
@Test
publicvoidstudent_findById() {
try{
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student/1");
Representation representation = client.get();
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
publicvoidstudent_delete() {
try{
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student/1");
Representation representation = client.delete();
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
@Test
publicvoidstudent_put() {
try{
Student student = newStudent("Test_Put", 0, 23);
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student/2");
Representation representation = client.put(student, MediaType.APPLICATION_JAVA_OBJECT);
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
/**
* StudentResource中第二种传入参数和返回值的方式的客户端调用方式
*/
@Test
publicvoidstudent_put_other() {
try{
Form queryForm = newForm();
queryForm.add("name", "steven4");
queryForm.add("sex", "2");
queryForm.add("age", "300");
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student/2");
Representation representation = client.put(queryForm.getWebRepresentation());
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
@Test
publicvoidstudent_post() {
try{
Student student = newStudent("Test_Put", 0, 23);
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student");
Representation representation = client.post(student, MediaType.APPLICATION_JAVA_OBJECT);
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
@Test
publicvoidstudent_getAll() {
try{
ClientResource client = newClientResource(
"http://localhost:8080/RestletService/student");
Representation representation = client.get();
System.out.println(representation.getText());
} catch(Exception e) {
e.printStackTrace();
}
}
}

说明：以上的org.restlet.Application的使用示例。

9、org.restlet.Component的使用
在上面的实例中，如果需要加入Teacher等更多资源时，或许为了业务逻辑的分离，就不能再把TeacherResource也在StudentApplication中进行绑定。

解决办法是如同上面所示建立Teacher相关的Resource和针对Teacher的org.restlet.Application扩展，然后扩展org.restlet.Component如下：

publicclassRestSimpleComponent extendsComponent {
publicRestSimpleComponent() {
getDefaultHost().attach("/stu",newStudentApplication());
getDefaultHost().attach("/tea",newTeacherApplication());
}
}

再修改web.xml中<context-param/>如下：

<context-param>
<!-- <param-name>org.restlet.application</param-name>
<param-value>com.rc.rl.RestSimpleApplication</param-value> -->
<param-name>org.restlet.component</param-name>
<param-value>com.rc.rl.RestSimpleComponent</param-value>
</context-param>

注意：通过如上配置之后，访问的URI需要加上Component中添加的路径，如之前的 http://localhost:8080/RestletService/student/1将变更为 http://localhost:8080/RestletService/stu/student/1

本文出自 “袭冷” 博客，请务必保留此出处http://xilen.blog.51cto.com/8455881/1348735