java 使用 apache HttpClient 连接到 Web 服务
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Connecting to Web Service with apache HttpClient
提问by Thorn
The Appache HTTP Componentslibrary seems to work fine for communicating with a regular web site, but is unable to connect to a web service.
该Appache HTTP组件库似乎好工作与正规网站通信，但是无法连接到Web服务。
I am building come components to run inside a Java Desktop application that will communicate with a Web Service-REST using the Jersey framework. The web service is running and I can communicate it with my web browser and with the Test-Web-Service function in netbeans.
我正在构建要在 Java 桌面应用程序中运行的组件，该应用程序将使用 Jersey 框架与 Web 服务-REST 进行通信。Web 服务正在运行，我可以与我的 Web 浏览器以及 netbeans 中的 Test-Web-Service 功能进行通信。
The client code works fine if I try to read from a regular web page or even the default page for the Glassfish web server running on my machine. Why is it that when I try to reach the web service with my client program (code below) do I get a 404 Not Found error from the web server?
如果我尝试从常规网页或什至在我的机器上运行的 Glassfish Web 服务器的默认页面进行读取，则客户端代码工作正常。为什么当我尝试使用我的客户端程序（下面的代码）访问 Web 服务时，我会从 Web 服务器收到 404 Not Found 错误？
import java.io.*;
import org.apache.http.*;
import org.apache.http.client.*;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.client.methods.*; //HttpHead, HttpPut, HttpGet, etc...
import org.apache.http.util.EntityUtils;
public class ApacheClientDemo {
public static void demo() throws IOException {
String uri = "http://localhost:8080/Proctorest/resources/helloWorld";
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(uri);
HttpResponse response = httpclient.execute(httpget);
System.out.println(response.getStatusLine().toString());
HttpEntity entity = response.getEntity();
System.out.println();
System.out.println(EntityUtils.toString(entity));
}
public static void main(String[] args) {
try {
demo();
}
catch(IOException ioe) {
System.out.println(ioe);
}
}
}
When going to a regular web site on-line or a non-web service site hosted locally, the output is
当转到在线的常规网站或本地托管的非 Web 服务站点时，输出为
HTTP/1.1 200 OK
Followed by the content of the web page.
其次是网页内容。
The code above gives me
上面的代码给了我
HTTP/1.1 404 Not Found
编辑：以下是 Web 服务的代码。Web 服务代码是从 Netbeans 示例项目生成的。
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package helloworld;
import javax.ejb.EJB;
import javax.ejb.Stateless;
import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.PUT;
import javax.ws.rs.Produces;
import javax.ws.rs.Consumes;
/**
* REST Web Service
*
* @author mkuchtiak
*/
@Stateless
@Path("/helloWorld")
public class HelloWorldResource {
@EJB
private NameStorageBean nameStorage;
/**
* Retrieves representation of an instance of helloworld.HelloWorldResource
* @return an instance of java.lang.String
*/
@GET
@Produces("text/html")
public String getXml() {
return "<html><body><h1>Hello "+nameStorage.getName()+"!</h1></body></html>";
}
/**
* PUT method for updating an instance of HelloWorldResource
* @param content representation for the resource
* @return an HTTP response with content of the updated or created resource.
*/
@PUT
@Consumes("text/plain")
public void putXml(String content) {
nameStorage.setName(content);
}
}
/////////// NameStorageBean .java
import javax.ejb.Singleton;
/** Singleton session bean used to store the name parameter for "/helloWorld" resource
*
* @author mkuchtiak
*/
@Singleton
public class NameStorageBean {
// name field
private String name = "World";
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
采纳答案by moskito-x
I can not see how you deploy the service.
我看不到您如何部署服务。
try change (camel case is unusual for a service)
尝试更改（骆驼案例对于服务来说是不寻常的）
String uri = "http://localhost:8080/Proctorest/resources/helloWorld";
to lowercase "helloworld"
小写“helloworld”
String uri = "http://localhost:8080/Proctorest/resources/helloworld";
or try
或尝试
String uri = "http://localhost:8080/helloworld";
HOW TO GET ROUTE
如何获得路线
U:...\HelloWorld1\HelloWorld1\web\WEB-INF\sun-web.xml
U:...\HelloWorld1\HelloWorld1\web\WEB-INF\sun-web.xml
<sun-web-app error-url="">
<context-root>/HW</context-root>
<class-loader delegate="true"/>
<jsp-config>
<property name="keepgenerated" value="true">
<description>Keep a copy of the generated servlet class' java code.</description>
</property>
</jsp-config>
</sun-web-app>
a) //localhost:8080/HWfrom <context-root>/HW</context-root>
a) //localhost:8080/硬件来自<context-root>/HW</context-root>
U:...\HelloWorld1\HelloWorld1\web\WEB-INF\web.xml
U:...\HelloWorld1\HelloWorld1\web\WEB-INF\web.xml
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<servlet-name>ServletAdaptor</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>ServletAdaptor</servlet-name>
<url-pattern>/hw/*</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
b) //localhost:8080/HW/hwfrom <url-pattern>/hw/*</url-pattern>
b) //localhost:8080/HW/ hwfrom<url-pattern>/hw/*</url-pattern>
U:....\HelloWorld1\HelloWorld1\src\java\helloworld\HelloWorldResource.java
U:....\HelloWorld1\HelloWorld1\src\java\helloworld\HelloWorldResource.java
.....
/**
* REST Web Service
*
* @author mkuchtiak
*/
@Stateless
@Path("/helloworld")
public class HelloWorldResource {
....
c) //localhost:8080/HW/hw/helloworldfrom @Path("/helloworld")
c) //localhost:8080/HW/hw/ helloworldfrom@Path("/helloworld")
put a)b)c) parts from your 3 files together.
将 3 个文件中的 a)b)c) 部分放在一起。
Notice: the url Netbeans shows is wrong, only /HW is correct
注意：Netbeans 显示的 url 是错误的，只有 /HW 是正确的
...
Incrementally deploying HelloWorld1
Completed incremental distribution of HelloWorld1
run-deploy:
Browsing: http://localhost:8080/HW/resources/helloWorld
...
....
public static void demo() throws IOException {
String uri = "http://localhost:8080/HW/hw/helloworld";
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(uri);
HttpResponse response = httpclient.execute(httpget);
System.out.println(response.getStatusLine().toString());
HttpEntity entity = response.getEntity();
System.out.println();
System.out.println(EntityUtils.toString(entity));
}
....
OUTPUT
输出
debug:
HTTP/1.1 200 OK
<html><body><h1>Hello World!</h1></body></html>
