例子
让我们更新在 RESTful Web 服务中创建的示例，创建可以执行 CRUD（创建、读取、更新、删除）操作的
Web 服务的第一个应用程序教程。为简单起见，我们使用文件 I/O 来替换数据库操作。
更新 UserService.java, User.java,UserDao.java com.jc2182 包下的文件。
User.java
package com.jc2182;
import java.io.Serializable;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "user")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private int id;
private String name;
private String profession;
public User(){}
public User(int id, String name, String profession){
this.id = id;
this.name = name;
this.profession = profession;
}
public int getId() {
return id;
}
@XmlElement
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
@XmlElement
public void setName(String name) {
this.name = name;
}
public String getProfession() {
return profession;
}
@XmlElement
public void setProfession(String profession) {
this.profession = profession;
}
@Override
public boolean equals(Object object){
if(object == null){
return false;
}else if(!(object instanceof User)){
return false;
}else {
User user = (User)object;
if(id == user.getId()
&& name.equals(user.getName())
&& profession.equals(user.getProfession())
){
return true;
}
}
return false;
}
}
UserDao.java
package com.jc2182;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;
public class UserDao {
public List<User> getAllUsers(){
List<User> userList = null;
try {
File file = new File("Users.dat");
if (!file.exists()) {
User user = new User(1, "Mahesh", "Teacher");
userList = new ArrayList<User>();
userList.add(user);
saveUserList(userList);
}
else{
FileInputStream fis = new FileInputStream(file);
ObjectInputStream ois = new ObjectInputStream(fis);
userList = (List<User>) ois.readObject();
ois.close();
}
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return userList;
}
public User getUser(int id){
List<User> users = getAllUsers();
for(User user: users){
if(user.getId() == id){
return user;
}
}
return null;
}
public int addUser(User pUser){
List<User> userList = getAllUsers();
boolean userExists = false;
for(User user: userList){
if(user.getId() == pUser.getId()){
userExists = true;
break;
}
}
if(!userExists){
userList.add(pUser);
saveUserList(userList);
return 1;
}
return 0;
}
public int updateUser(User pUser){
List<User> userList = getAllUsers();
for(User user: userList){
if(user.getId() == pUser.getId()){
int index = userList.indexOf(user);
userList.set(index, pUser);
saveUserList(userList);
return 1;
}
}
return 0;
}
public int deleteUser(int id){
List<User> userList = getAllUsers();
for(User user: userList){
if(user.getId() == id){
int index = userList.indexOf(user);
userList.remove(index);
saveUserList(userList);
return 1;
}
}
return 0;
}
private void saveUserList(List<User> userList){
try {
File file = new File("Users.dat");
FileOutputStream fos;
fos = new FileOutputStream(file);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(userList);
oos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
UserService.java
package com.jc2182;
import java.io.IOException;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.OPTIONS;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
@Path("/UserService")
public class UserService {
UserDao userDao = new UserDao();
private static final String SUCCESS_RESULT="<result>success</result>";
private static final String FAILURE_RESULT="<result>failure</result>";
@GET
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
public List<User> getUsers(){
return userDao.getAllUsers();
}
@GET
@Path("/users/{userid}")
@Produces(MediaType.APPLICATION_XML)
public User getUser(@PathParam("userid") int userid){
return userDao.getUser(userid);
}
@POST
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public String createUser(@FormParam("id") int id,
@FormParam("name") String name,
@FormParam("profession") String profession,
@Context HttpServletResponse servletResponse) throws IOException{
User user = new User(id, name, profession);
int result = userDao.addUser(user);
if(result == 1){
return SUCCESS_RESULT;
}
return FAILURE_RESULT;
}
@PUT
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public String updateUser(@FormParam("id") int id,
@FormParam("name") String name,
@FormParam("profession") String profession,
@Context HttpServletResponse servletResponse) throws IOException{
User user = new User(id, name, profession);
int result = userDao.updateUser(user);
if(result == 1){
return SUCCESS_RESULT;
}
return FAILURE_RESULT;
}
@DELETE
@Path("/users/{userid}")
@Produces(MediaType.APPLICATION_XML)
public String deleteUser(@PathParam("userid") int userid){
int result = userDao.deleteUser(userid);
if(result == 1){
return SUCCESS_RESULT;
}
return FAILURE_RESULT;
}
@OPTIONS
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
public String getSupportedOperations(){
return "<operations>GET, PUT, POST, DELETE</operations>";
}
}
现在使用 Eclipse，将您的应用程序导出为一个 war 文件并在 tomcat 中部署它。要使用 Eclipse 创建 WAR 文件，请按照选项File -> export -> Web > War File最后选择项目 UserManagement 和目标文件夹。要在 Tomcat 中部署 war 文件，请将 UserManagement.war 放在Tomcat Installation Directory > webapps 目录并启动Tomcat。
