Question

没有maven，gradle或类似的东西。我怎样才能解决下面的问题？我读过有关java classpath的问题。但我需要深入了解如何找到一个包并将其包含在我的项目中。确切地说，如何在此项目中包括org.apache.http.client.methods.HttpGet。

这是HelloWorld.java文件

import java.io.IOException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.HttpClient;
import org.apache.http.impl.client.HttpClientBuilder;

public class HelloWorld {
    public static void main (String[] args) throws IOException {
        Runtime.getRuntime().exec("clear");
        System.out.println("Console!!!");


        String url = "http://www.example.com";
        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet(url);
        request.addHeader("User-Agent", USER_AGENT);
        HttpResponse response = client.execute(request);


        BufferReader rd = new BufferReader(
            new InputStreamReader(
                response.getEntity().getContent()
            )
        );


        StringBuffer result = new StringBuffer();
        String line = "";
        while ((line = rd.readLine()) != null) {
            result.append(line);
        }


        System.out.println(result);
    }
}

这是命令

javac HelloWorld.java

这是输出

HelloWorld.java:2: error: package org.apache.http.client.methods does not exist
import org.apache.http.client.methods.HttpGet;
                                     ^
HelloWorld.java:3: error: package org.apache.http.client does not exist
import org.apache.http.client.HttpClient;
                             ^
HelloWorld.java:4: error: package org.apache.http.impl.client does not exist
import org.apache.http.impl.client.HttpClientBuilder;
                                  ^
HelloWorld.java:13: error: cannot find symbol
        HttpClient client = HttpClientBuilder.create().build();
        ^
  symbol:   class HttpClient
  location: class HelloWorld
HelloWorld.java:13: error: cannot find symbol
        HttpClient client = HttpClientBuilder.create().build();
                            ^
  symbol:   variable HttpClientBuilder
  location: class HelloWorld
HelloWorld.java:14: error: cannot find symbol
        HttpGet request = new HttpGet(url);
        ^
  symbol:   class HttpGet
  location: class HelloWorld
HelloWorld.java:14: error: cannot find symbol
        HttpGet request = new HttpGet(url);
                              ^
  symbol:   class HttpGet
  location: class HelloWorld
HelloWorld.java:15: error: cannot find symbol
        request.addHeader("User-Agent", USER_AGENT);
                                        ^
  symbol:   variable USER_AGENT
  location: class HelloWorld
HelloWorld.java:16: error: cannot find symbol
        HttpResponse response = client.execute(request);
        ^
  symbol:   class HttpResponse
  location: class HelloWorld
HelloWorld.java:19: error: cannot find symbol
        BufferReader rd = new BufferReader(
        ^
  symbol:   class BufferReader
  location: class HelloWorld
HelloWorld.java:19: error: cannot find symbol
        BufferReader rd = new BufferReader(
                              ^
  symbol:   class BufferReader
  location: class HelloWorld
HelloWorld.java:20: error: cannot find symbol
            new InputStreamReader(
                ^
  symbol:   class InputStreamReader
  location: class HelloWorld
12 errors

我该如何解决这个问题？如何添加供应商代码？我怎样才能导入org.apache.http.client.methods.HttpGet？ ...

抱歉，我来自PHP。在PHP中我们有作曲家和包装。在Java世界？

Answer 1

如果您已下载包含apache http stuff的jar文件，请以这种方式更改您的命令行

javac -classpath <the_location_of_the_jar>;. HelloWorld.java

分号分隔一个或多个位置，点表示当前目录

Answer 2

首先，您提供的代码有一些语法错误： 1）你应该导入你在java文件中使用的所有类; 2）你有“BufferedReader”的拼写.3）你的代码中的USER_AGENT没有定义。一个修改过的代码会这样：包com; import java.io。*;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.*;
import org.apache.http.client.*;
import org.apache.http.impl.client.HttpClientBuilder;

public class HelloWorld {
    public static void main (String[] args) throws IOException {
        Runtime.getRuntime().exec("clear");
        System.out.println("Console!!!");


        String url = "http://www.example.com";
        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet(url);
        request.addHeader("User-Agent", "XXXX");
        HttpResponse response = client.execute(request);


        BufferedReader rd = new BufferedReader (
            new InputStreamReader(
                response.getEntity().getContent()
            )
        );


        StringBuffer result = new StringBuffer();
        String line = "";
        while ((line = rd.readLine()) != null) {
            result.append(line);
        }
        System.out.println(result);
    }
}

然后，我们可以开始使用javac来编译你的代码。你的代码引用了其他类，比如HttpClient或BufferedReader等。所以你应该通过两种替代方法告诉javac包含引用类的jar： 1）配置系统env变量“CLASSPATH”，其值是以分号分隔的包含所有引用类的jar的列表。 2）为你的javac命令添加-classpath选项，该选项的值与“CLASSPATH”的值相同。对于我的windows环境，我用这个命令测试： C:\Users\Administrator>javac -classpath "C:\Program Files\Java\jdk1.8.0_66\jre\lib;C:\Program Files\Java\jdk1.8.0_66\lib;C:\com\lib\httpclient-4.5.2.jar;C:\c\lib\httpclient-cache-4.5.2.jar;C:\com\lib\httpcore-4.4.4.jar;C:\com\lib\httpclient-win-4.5.2.jar;C:\com\lib\httpmime-4.5.2.jar" c:\com\HelloWorld.java

我希望这可以帮到你。

错误：包org.apache.http.client.methods不存在

2 个答案: