java代码使用Get请求或者Post请求获取网络内容

桃扇骨 2021-09-21 13:34 278阅读 0赞

引入的依赖包，也可以去 阿里仓库下载   ————>[前往阿里云仓库][Link 1]

<dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
      <version>3.7</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.1.RELEASE</version>
    </dependency>

一个Get Post请求的java代码

import org.apache.commons.lang3.StringUtils;
    import org.springframework.util.StreamUtils;
    
    import java.io.*;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.nio.charset.Charset;
    import java.util.Map;
    
    public class HttpUtil {
    
        /**
         * post请求
         * @param urlStr
         * @param param
         * @param userAgent
         * @return
         */
        public static String httpPost(String urlStr,String param,String userAgent){
            try {
                URL url = new URL(urlStr);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("POST");
                conn.setRequestProperty("Content-Type",
                        "application/x-www-form-urlencoded");
                conn.setReadTimeout(5000);
                conn.setConnectTimeout(60 * 1000);
                if(StringUtils.isNotBlank(userAgent)){
                    conn.setRequestProperty("User-Agent",
                            userAgent);
                }
                conn.setUseCaches(false);
                conn.setDoInput(true);
                conn.setDoOutput(true);
                BufferedOutputStream out = new BufferedOutputStream(conn
                        .getOutputStream());
                BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream(),"utf-8"));
                bw.write(param);
                bw.flush();
                bw.close();
    
                if (conn.getResponseCode()==200){
                    BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
                    String tempStr = null;
                    String str = "";
                    while ((tempStr=br.readLine())!=null){
                        str +=tempStr;
                    }
                    br.close();
                    return str;
                }
            }catch (Exception e){
                e.printStackTrace();
            }
            return null;
        }
        /**
         * post请求
         * @param urlStr
         * @param xmlParam
         * @return
         */
        public static String httpPost(String urlStr,String xmlParam){
            return httpPost(urlStr,xmlParam,null);
        }
    
    
        /**
         * 调用外部接口，并返回响应结果
         * @param httpUrl
         * @param params
         * @return
         * @throws Exception
         */
        public static String sendHttpPostRequest(String httpUrl, Map<String, String> params) throws Exception{
    
            URL url = new URL(httpUrl);
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
    
            if(params != null && params.size() > 0){
                StringBuilder sb = new StringBuilder();
                for(Map.Entry<String, String> entry : params.entrySet()){
                    sb.append("&").append(entry.getKey()).append("=").append(entry.getValue());
                }
                conn.getOutputStream().write(sb.substring(1).getBytes("utf-8"));
            }
            conn.connect();
            String responseContent = StreamUtils.copyToString(conn.getInputStream(), Charset.forName("utf-8"));
    
            conn.disconnect();
            return responseContent;
        }
    
        public static String sendHttpGetRequest(String httpUrl, Map<String, String> params) throws Exception{
    
            try {
                if(params != null && params.size() > 0){
                    StringBuilder sb = new StringBuilder();
                    for(Map.Entry<String, String> entry : params.entrySet()){
                        sb.append("&").append(entry.getKey()).append("=").append(entry.getValue());
                    }
                    sb = new StringBuilder(sb.substring(1));
                    if(httpUrl.contains("?")){
                        httpUrl += "&"+sb.toString();
                    }else{
                        httpUrl += "?"+sb.toString();
                    }
                }
                URL url = new URL(httpUrl);
                HttpURLConnection conn = (HttpURLConnection)url.openConnection();
                conn.setRequestMethod("GET");
                conn.setDoOutput(true);
                conn.connect();
                String responseContent = StreamUtils.copyToString(conn.getInputStream(), Charset.forName("utf-8"));
                conn.disconnect();
                return responseContent;
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }
    
    
        //获得网络路径
        public static InputStream getImageStream(String url) throws Exception{
            HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
            connection.setReadTimeout(5000);
            connection.setConnectTimeout(5000);
            connection.setRequestMethod("GET");
            connection.addRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36");
            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                return connection.getInputStream();
            }else{
                throw new Exception("响应状态：" + connection.getResponseCode() + "\n" +
                        "响应内容：" + connection.getResponseMessage());
            }
        }
    
        //判断当前请求是否有效
        public static boolean sendGetRequestAck(String url) throws Exception{
            HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
            connection.setReadTimeout(5000);
            connection.setConnectTimeout(5000);
            connection.setRequestMethod("GET");
            connection.addRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36");
            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                return true;
            }else{
                return false;
            }
        }
    
        //把字节流转换成字节数组
        public static byte[] toByteArray(InputStream input) {
            try {
                ByteArrayOutputStream output = new ByteArrayOutputStream();
                byte[] buffer = new byte[1024*4];
                int n = 0;
                while (-1 != (n = input.read(buffer))) {
                    output.write(buffer, 0, n);
                }
                return output.toByteArray();
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }
    
        //把字节数组转换成字节流
        public static InputStream toInputStream(byte[] bytes){
            return new ByteArrayInputStream(bytes);
        }
    
        //字节流转换字节流
        public static InputStream toInputStream(InputStream input){
            return toInputStream(toByteArray(input));
        }
    }

[Link 1]: https://maven.aliyun.com/mvn/search