Climbing pit record - Android interacts with the server (1)

Others 2022-04-22 09:26:01 views: 0

Climbing pit record - Android interacts with the server (1)

Convention:
The interaction between the Android client and the server is implemented: the
client assembles the HTTPrequest , sends it to the server, and obtains the JSONstring returned by the server.

The client assembles the HTTP request code

version 1

  1. This version is sufficient in most cases. The premise is that the parameters of the request are not included +. If it is included +, the server will not receive the correct parameters. For example, abc+defwhen , the server receives it abc def.
  2. When using , HttpURLConnectionthe space is encoded as a plus sign, so the passed parameter is obviously a plus sign, but the obtained value becomes a space .
import com.orhanobut.logger.Logger;

import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Created by administrator on 2018/4/3.
 */

public class HttpRequestUtils {


    /**
     * 发送post请求
     * @param urlParam
     * @param params
     * @param charset
     * @return
     */
    public static String sendPost(String urlParam, Map<String, Object> params, String charset) {
        StringBuffer resultBuffer = null;
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> e : params.entrySet()) {
                sbParams.append(e.getKey());
                sbParams.append("=");
                sbParams.append(e.getValue());
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        OutputStreamWriter osw = null;
        BufferedReader br = null;
        // 发送请求
        try {
            URL url = new URL(urlParam);
            con = (HttpURLConnection) url.openConnection();
            con.setRequestMethod("POST");
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setUseCaches(false);
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            if (sbParams != null && sbParams.length() > 0) {
                osw = new OutputStreamWriter(con.getOutputStream(), charset);
                osw.write(sbParams.substring(0, sbParams.length() - 1));
                osw.flush();
            }
            // 读取返回内容
            resultBuffer = new StringBuffer();
            int contentLength = Integer.parseInt(con.getHeaderField("Content-Length"));
            if (contentLength > 0) {
                br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));
                String temp;
                while ((temp = br.readLine()) != null) {
                    resultBuffer.append(temp);
                }
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (osw != null) {
                try {
                    osw.close();
                } catch (IOException e) {
                    osw = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }

        return resultBuffer.toString();
    }

    /**
     * 发送get请求
     * @param urlParam
     * @param params
     * @param charset
     * @return
     */
    public static String sendGet(String urlParam, Map<String, Object> params, String charset) {
        StringBuffer resultBuffer = null;
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> entry : params.entrySet()) {
                sbParams.append(entry.getKey());
                sbParams.append("=");
                sbParams.append(entry.getValue());
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        BufferedReader br = null;
        try {
            URL url = null;
            if (sbParams != null && sbParams.length() > 0) {
                url = new URL(urlParam + "?" + sbParams.substring(0, sbParams.length() - 1));
            } else {
                url = new URL(urlParam);
            }
            con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            con.connect();
            resultBuffer = new StringBuffer();
            br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));
            String temp;
            while ((temp = br.readLine()) != null) {
                resultBuffer.append(temp);
            }
        } catch (Exception e) {
//            throw new RuntimeException(e);
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }
        String result = null;
        try {
            result = resultBuffer.toString();
        } catch (Exception e) {
        }
        return result;
    }

    /**
     * 发送get请求并保存下载文件
     * @param urlParam
     * @param params
     * @param fileSavePath
     */
    public static void sendGetAndSaveFile(String urlParam, Map<String, Object> params, String fileSavePath) {
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> entry : params.entrySet()) {
                sbParams.append(entry.getKey());
                sbParams.append("=");
                sbParams.append(entry.getValue());
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        BufferedReader br = null;
        FileOutputStream os = null;
        try {
            URL url = null;
            if (sbParams != null && sbParams.length() > 0) {
                url = new URL(urlParam + "?" + sbParams.substring(0, sbParams.length() - 1));
            } else {
                url = new URL(urlParam);
            }
            con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            con.connect();
            InputStream is = con.getInputStream();
            os = new FileOutputStream(fileSavePath);
            byte buf[] = new byte[1024];
            int count = 0;
            while ((count = is.read(buf)) != -1) {
                os.write(buf, 0, count);
            }
            os.flush();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    os = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }
    }
}

Version 2

The way to solve the problems that may occur in version 1 is relatively simple, just +replace %2B.
code show as below:

if (params != null && params.size() > 0) {
       for (Entry<String, Object> e : params.entrySet()) {
           sbParams.append(e.getKey());
           sbParams.append("=");
           sbParams.append(e.getValue().toString().replace("+", "%2B"));
           sbParams.append("&");
       }
  }

It should be noted that parameters should not be included in the name +. If there is +, then when the server obtains the variable, it will not be able to obtain the corresponding variable due to the wrong variable name.

package com.nexcool.online.utils;

import com.orhanobut.logger.Logger;

import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Created by administrator on 2018/4/3.
 */

public class HttpRequestUtils {


    /**
     * 发送post请求
     * @param urlParam
     * @param params
     * @param charset
     * @return
     */
    public static String sendPost(String urlParam, Map<String, Object> params, String charset) {
        StringBuffer resultBuffer = null;
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> e : params.entrySet()) {
                sbParams.append(e.getKey());
                sbParams.append("=");
                sbParams.append(e.getValue().toString().replace("+", "%2B"));
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        OutputStreamWriter osw = null;
        BufferedReader br = null;
        // 发送请求
        try {
            URL url = new URL(urlParam);
            con = (HttpURLConnection) url.openConnection();
            con.setRequestMethod("POST");
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setUseCaches(false);
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            if (sbParams != null && sbParams.length() > 0) {
                osw = new OutputStreamWriter(con.getOutputStream(), charset);
                osw.write(sbParams.substring(0, sbParams.length() - 1));
                osw.flush();
            }
            // 读取返回内容
            resultBuffer = new StringBuffer();
            int contentLength = Integer.parseInt(con.getHeaderField("Content-Length"));
            if (contentLength > 0) {
                br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));
                String temp;
                while ((temp = br.readLine()) != null) {
                    resultBuffer.append(temp);
                }
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (osw != null) {
                try {
                    osw.close();
                } catch (IOException e) {
                    osw = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }

        return resultBuffer.toString();
    }

    /**
     * 发送get请求
     * @param urlParam
     * @param params
     * @param charset
     * @return
     */
    public static String sendGet(String urlParam, Map<String, Object> params, String charset) {
        StringBuffer resultBuffer = null;
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> entry : params.entrySet()) {
                sbParams.append(entry.getKey());
                sbParams.append("=");
                sbParams.append(entry.getValue().toString().replace("+", "%2B"));
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        BufferedReader br = null;
        try {
            URL url = null;
            if (sbParams != null && sbParams.length() > 0) {
                url = new URL(urlParam + "?" + sbParams.substring(0, sbParams.length() - 1));
            } else {
                url = new URL(urlParam);
            }
            con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            con.connect();
            resultBuffer = new StringBuffer();
            br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));
            String temp;
            while ((temp = br.readLine()) != null) {
                resultBuffer.append(temp);
            }
        } catch (Exception e) {
//            throw new RuntimeException(e);
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }
        String result = null;
        try {
            result = resultBuffer.toString();
        } catch (Exception e) {
        }
        return result;
    }

    /**
     * 发送get请求并保存下载文件
     * @param urlParam
     * @param params
     * @param fileSavePath
     */
    public static void sendGetAndSaveFile(String urlParam, Map<String, Object> params, String fileSavePath) {
        // 构建请求参数
        StringBuffer sbParams = new StringBuffer();
        if (params != null && params.size() > 0) {
            for (Entry<String, Object> entry : params.entrySet()) {
                sbParams.append(entry.getKey());
                sbParams.append("=");
                sbParams.append(entry.getValue().toString().replace("+", "%2B"));
                sbParams.append("&");
            }
        }
        HttpURLConnection con = null;
        BufferedReader br = null;
        FileOutputStream os = null;
        try {
            URL url = null;
            if (sbParams != null && sbParams.length() > 0) {
                url = new URL(urlParam + "?" + sbParams.substring(0, sbParams.length() - 1));
            } else {
                url = new URL(urlParam);
            }
            con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            con.connect();
            InputStream is = con.getInputStream();
            os = new FileOutputStream(fileSavePath);
            byte buf[] = new byte[1024];
            int count = 0;
            while ((count = is.read(buf)) != -1) {
                os.write(buf, 0, count);
            }
            os.flush();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    os = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    br = null;
                    throw new RuntimeException(e);
                } finally {
                    if (con != null) {
                        con.disconnect();
                        con = null;
                    }
                }
            }
        }
    }
}

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