I am trying to learn simple restful web services. So, I looked up an example and followed it step by step but I am stuck with Error 404 when trying to deploy the project. Any idea why?
File: web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>UserManagement</display-name>
<servlet>
<servlet-name>Jersey RESTful Application</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.tutorialspoint</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Jersey RESTful Application</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
</web-app>
File: User.java:
package com.tutorialspoint;
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;
}
}
File: UserDao.java
package com.tutorialspoint;
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 {
@SuppressWarnings("unchecked")
public List<User> getAllUsers(){
List<User> userList = null;
try {
File file = new File("Users.dat");
if (!file.exists()) {
User user = new User(1, "Mahesh", "Developer");
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;
}
private void saveUserList(List<User> userList) {
// TODO Auto-generated method stub
try {
File file = new File ("User.dat");
FileOutputStream fos = new FileOutputStream (file);
ObjectOutputStream oos = new ObjectOutputStream (fos);
oos.writeObject(userList);
oos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
File: UserService.java
package com.tutorialspoint;
import java.util.List;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
@Path("/UserService")
public class UserService {
UserDao userDao = new UserDao();
@GET
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
public List<User> getUsers() {
return userDao.getAllUsers();
}
}
Here's what I am getting back Error 404 screenshot
Besides the possibility that your application is not even deployed (also 404):
The path you configured your rest service to answer is
<Your application context>/rest/UserService/users
<Your application context>
seems to be /UserManagement
.
/rest
is configured in your web.xml
in the jersey servlet mapping /UserService
is configured in your UserService.java
file in the @Path
annotation /users
is configured in UserService.java
file on the method's @Path
annotation. This should be @Path("users")
. Your screenshot shows you are calling /UserManagement
, which may be the context of your application, but is not the path to your service.
You can change you web.xml file. There is some problem with webxml file. Use this web.xml file use below code.
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>User Management</display-name>
<servlet>
<servlet-name>Jersey RESTful Application</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.tutorialspoint</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Jersey RESTful Application</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
</web-app>
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