Android后台数据接口交互实现注册功能
首先,在ecplise里面新建一个叫做TestServices的web工程。在WebContent--WEB-INF--libs文件夹下导入两个jar包:mysql-connector-java-6.0.2和gson-2.3.1
mysql-connector-java-6.0.2下载链接:https://pan.baidu.com/s/1eRMByB9ERVC_T51ZBw5Q8Q 提取码: th9l
gson-2.3.1下载链接:https://pan.baidu.com/s/1NpYioUbOJTj8B1idDVupqQ 提取码: 9ir9
mysql数据库表如下:
源代码如下:
DBUtils.java:
package com.xhj.db; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBUtils { private Connection conn; private String url = "jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC"; // 指定连接数据库的URL private String user = "root"; // 指定连接数据库的用户名 private String password = ""; // 指定连接数据库的密码 private Statement sta; private ResultSet rs; // 打开数据库连接 public void openConnect() { try { // 加载数据库驱动 Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url, user, password);// 创建数据库连接 if (conn != null) { System.out.println("数据库连接成功"); // 连接成功的提示信息 } } catch (Exception e) { System.out.println("ERROR: " + e.getMessage()); } } // 获得查询user表后的数据集 public ResultSet getUser() { // 创建 statement对象 try { sta = conn.createStatement(); // 执行SQL查询语句 rs = sta.executeQuery("select * from user"); } catch (SQLException e) { e.printStackTrace(); } return rs; } // 判断数据库中是否存在某个用户名及其密码,注册和登录的时候判断 public boolean isExistInDB(String username, String password) { boolean isFlag = false; // 创建 statement对象 try { System.out.println("判断用户名密码"); sta = conn.createStatement(); // 执行SQL查询语句 rs = sta.executeQuery("select * from user");// 获得结果集 if (rs != null) { while (rs.next()) { // 遍历结果集 if (rs.getString("user_name").equals(username)) { if (rs.getString("user_pwd").equals(password)) { isFlag = true; break; } } } } } catch (SQLException e) { e.printStackTrace(); isFlag = false; } return isFlag; } // 注册 将用户名和密码插入到数据库(id设置的是自增长的,因此不需要插入) public boolean insertDataToDB(String username, String password) { String sql = " insert into user ( user_name , user_pwd ) values ( " + "'" + username + "', " + "'" + password + "' )"; try { sta = conn.createStatement(); // 执行SQL查询语句 return sta.execute(sql); } catch (SQLException e) { e.printStackTrace(); } return false; } // 关闭数据库连接 public void closeConnect() { try { if (rs != null) { rs.close(); } if (sta != null) { sta.close(); } if (conn != null) { conn.close(); } System.out.println("关闭数据库连接成功"); } catch (SQLException e) { System.out.println("Error: " + e.getMessage()); } } }
BaseBean.java:
package com.xhj.domain; public class BaseBean { private int code; private String msg; private Object data; public int getCode() { return code; } public void setCode(int code) { this.code = code; } public String getMsg() { return msg; } public void setMsg(String msg) { this.msg = msg; } public Object getData() { return data; } public void setData(Object data) { this.data = data; } }
UserBean.java:
package com.xhj.domain; import java.io.Serializable; public class UserBean implements Serializable{ private int id; private String username; private String password; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
LoginDateServlet.java:
package com.xhj.servlet; import java.io.IOException; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.google.gson.Gson; import com.xhj.db.DBUtils; import com.xhj.domain.BaseBean; import com.xhj.domain.UserBean; public class LoginDateServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("request--->"+request.getRequestURL()+"===="+request.getParameterMap().toString()); String username = request.getParameter("username"); // 获取客户端传过来的参数 String password = request.getParameter("password"); response.setContentType("text/html;charset=utf-8"); if (username == null || username.equals("") || password == null || password.equals("")) { System.out.println("用户名或密码为空"); return; } // 请求数据库 DBUtils dbUtils = new DBUtils(); dbUtils.openConnect(); // 打开数据库连接 BaseBean data = new BaseBean(); // 基类对象,回传给客户端的json对象 UserBean userBean = new UserBean(); // user的对象 if (dbUtils.isExistInDB(username, password)) { // 判断账号是否存在 data.setCode(-1); data.setData(userBean); data.setMsg("该账号已存在"); } else if (!dbUtils.insertDataToDB(username, password)) { // 注册成功 data.setCode(0); data.setMsg("注册成功!!"); ResultSet rs = dbUtils.getUser(); int id = -1; if (rs != null) { try { while (rs.next()) { if (rs.getString("user_name").equals(username) && rs.getString("user_pwd").equals(password)) { id = rs.getInt("user_id"); } } userBean.setId(id); } catch (SQLException e) { e.printStackTrace(); } } userBean.setUsername(username); userBean.setPassword(password); data.setData(userBean); } else { // 注册不成功,这里错误没有细分,都归为数据库错误 data.setCode(500); data.setData(userBean); data.setMsg("数据库错误"); } Gson gson = new Gson(); String json = gson.toJson(data); // 将对象转化成json字符串 try { response.getWriter().println(json); // 将json数据传给客户端 } catch (Exception e) { e.printStackTrace(); } finally { response.getWriter().close(); // 关闭这个流,不然会发生错误的 } dbUtils.closeConnect(); // 关闭数据库连接} } }
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>TestServices</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>LoginDateServlet</servlet-name> <servlet-class>com.xhj.servlet.LoginDateServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginDateServlet</servlet-name> <url-pattern>/servlet/LoginDateServlet</url-pattern> </servlet-mapping> </web-app>
到这里,点击LoginDateServlet.java,运行一下
因为我们没有传输用户名和密码,所以输出用户名或密码为空。
可以这样测试一下,在地址后面添加?username=123&password=123
可以看到,注册成功,数据已经保存到了数据库中
接下来需要在Android Studio里面,新建一个叫做TestNet的工程
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="com.example.testnet.MainActivity"> <EditText android:id="@+id/et_data_uname" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入用户名:" /> <EditText android:id="@+id/et_data_upass" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入密码:" android:inputType="number" /> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:onClick="loginGET" android:text="注册(GET)" /> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:onClick="loginPOST" android:text="注册(POST)" /> </LinearLayout>
activity_main.java:
package com.example.testnet; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.EditText; import androidx.appcompat.app.AppCompatActivity; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; import java.util.HashMap; public class MainActivity extends AppCompatActivity { String TAG = MainActivity.class.getCanonicalName(); private EditText et_data_uname; private EditText et_data_upass; private HashMap<String, String> stringHashMap; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_data_uname = (EditText) findViewById(R.id.et_data_uname); et_data_upass = (EditText) findViewById(R.id.et_data_upass); stringHashMap = new HashMap<>(); } public void loginGET(View view) { stringHashMap.put("username", et_data_uname.getText().toString()); stringHashMap.put("password", et_data_upass.getText().toString()); new Thread(getRun).start(); } public void loginPOST(View view) { stringHashMap.put("username", et_data_uname.getText().toString()); stringHashMap.put("password", et_data_upass.getText().toString()); new Thread(postRun).start(); } /** * get请求线程 */ Runnable getRun = new Runnable() { @Override public void run() { // TODO Auto-generated method stub requestGet(stringHashMap); } }; /** * post请求线程 */ Runnable postRun = new Runnable() { @Override public void run() { // TODO Auto-generated method stub requestPost(stringHashMap); } }; /** * get提交数据 * * @param paramsMap */ private void requestGet(HashMap<String, String> paramsMap) { try { String baseUrl = "http://10.0.2.2:8080/TestServices/servlet/LoginDateServlet?"; StringBuilder tempParams = new StringBuilder(); int pos = 0; for (String key : paramsMap.keySet()) { if (pos > 0) { tempParams.append("&"); } tempParams.append(String.format("%s=%s", key, URLEncoder.encode(paramsMap.get(key), "utf-8"))); pos++; } Log.e(TAG,"params--get-->>"+tempParams.toString()); String requestUrl = baseUrl + tempParams.toString(); // 新建一个URL对象 URL url = new URL(requestUrl); // 打开一个HttpURLConnection连接 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection(); // 设置连接主机超时时间 urlConn.setConnectTimeout(5 * 1000); //设置从主机读取数据超时 urlConn.setReadTimeout(5 * 1000); // 设置是否使用缓存 默认是true urlConn.setUseCaches(true); // 设置为Post请求 urlConn.setRequestMethod("GET"); //urlConn设置请求头信息 //设置请求中的媒体类型信息。 urlConn.setRequestProperty("Content-Type", "application/json"); //设置客户端与服务连接类型 urlConn.addRequestProperty("Connection", "Keep-Alive"); // 开始连接 urlConn.connect(); // 判断请求是否成功 if (urlConn.getResponseCode() == 200) { // 获取返回的数据 String result = streamToString(urlConn.getInputStream()); Log.e(TAG, "Get方式请求成功,result--->" + result); } else { Log.e(TAG, "Get方式请求失败"); } // 关闭连接 urlConn.disconnect(); } catch (Exception e) { Log.e(TAG, e.toString()); } } /** * post提交数据 * * @param paramsMap */ private void requestPost(HashMap<String, String> paramsMap) { try { String baseUrl = "http://10.0.2.2:8080/TestServices/servlet/LoginDateServlet"; //合成参数 StringBuilder tempParams = new StringBuilder(); int pos = 0; for (String key : paramsMap.keySet()) { if (pos >0) { tempParams.append("&"); } tempParams.append(String.format("%s=%s", key, URLEncoder.encode(paramsMap.get(key), "utf-8"))); pos++; } String params = tempParams.toString(); Log.e(TAG,"params--post-->>"+params); // 请求的参数转换为byte数组 // byte[] postData = params.getBytes(); // 新建一个URL对象 URL url = new URL(baseUrl); // 打开一个HttpURLConnection连接 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection(); // 设置连接超时时间 urlConn.setConnectTimeout(5 * 1000); //设置从主机读取数据超时 urlConn.setReadTimeout(5 * 1000); // Post请求必须设置允许输出 默认false urlConn.setDoOutput(true); //设置请求允许输入 默认是true urlConn.setDoInput(true); // Post请求不能使用缓存 urlConn.setUseCaches(false); // 设置为Post请求 urlConn.setRequestMethod("POST"); //设置本次连接是否自动处理重定向 urlConn.setInstanceFollowRedirects(true); //配置请求Content-Type // urlConn.setRequestProperty("Content-Type", "application/json");//post请求不能设置这个 // 开始连接 urlConn.connect(); // 发送请求参数 PrintWriter dos = new PrintWriter(urlConn.getOutputStream()); dos.write(params); dos.flush(); dos.close(); // 判断请求是否成功 if (urlConn.getResponseCode() == 200) { // 获取返回的数据 String result = streamToString(urlConn.getInputStream()); Log.e(TAG, "Post方式请求成功,result--->" + result); } else { Log.e(TAG, "Post方式请求失败"); } // 关闭连接 urlConn.disconnect(); } catch (Exception e) { Log.e(TAG, e.toString()); } } /** * 将输入流转换成字符串 * * @param is 从网络获取的输入流 * @return */ public String streamToString(InputStream is) { try { ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len = 0; while ((len = is.read(buffer)) != -1) { baos.write(buffer, 0, len); } baos.close(); is.close(); byte[] byteArray = baos.toByteArray(); return new String(byteArray); } catch (Exception e) { Log.e(TAG, e.toString()); return null; } } /** * 文件下载 * * @param fileUrl */ private void downloadFile(String fileUrl) { try { // 新建一个URL对象 URL url = new URL(fileUrl); // 打开一个HttpURLConnection连接 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection(); // 设置连接主机超时时间 urlConn.setConnectTimeout(5 * 1000); //设置从主机读取数据超时 urlConn.setReadTimeout(5 * 1000); // 设置是否使用缓存 默认是true urlConn.setUseCaches(true); // 设置为Post请求 urlConn.setRequestMethod("GET"); //urlConn设置请求头信息 //设置请求中的媒体类型信息。 urlConn.setRequestProperty("Content-Type", "application/json"); //设置客户端与服务连接类型 urlConn.addRequestProperty("Connection", "Keep-Alive"); // 开始连接 urlConn.connect(); // 判断请求是否成功 if (urlConn.getResponseCode() == 200) { String filePath = "";//下载文件保存在本地的地址 File descFile = new File(filePath); FileOutputStream fos = new FileOutputStream(descFile); ; byte[] buffer = new byte[1024]; int len; InputStream inputStream = urlConn.getInputStream(); while ((len = inputStream.read(buffer)) != -1) { // 写到本地 fos.write(buffer, 0, len); } } else { Log.e(TAG, "文件下载失败"); } // 关闭连接 urlConn.disconnect(); } catch (Exception e) { Log.e(TAG, e.toString()); } } /** * 文件上传 * * @param filePath * @param paramsMap */ private void upLoadFile(String filePath, HashMap<String, String> paramsMap) { try { String baseUrl = "https://xxx.com/uploadFile"; File file = new File(filePath); //新建url对象 URL url = new URL(baseUrl); //通过HttpURLConnection对象,向网络地址发送请求 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection(); //设置该连接允许读取 urlConn.setDoOutput(true); //设置该连接允许写入 urlConn.setDoInput(true); //设置不能适用缓存 urlConn.setUseCaches(false); //设置连接超时时间 urlConn.setConnectTimeout(5 * 1000); //设置连接超时时间 //设置读取超时时间 urlConn.setReadTimeout(5 * 1000); //读取超时 //设置连接方法post urlConn.setRequestMethod("POST"); //设置维持长连接 urlConn.setRequestProperty("connection", "Keep-Alive"); //设置文件字符集 urlConn.setRequestProperty("Accept-Charset", "UTF-8"); //设置文件类型 urlConn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + "*****"); String name = file.getName(); DataOutputStream requestStream = new DataOutputStream(urlConn.getOutputStream()); requestStream.writeBytes("--" + "*****" + "\r\n"); //发送文件参数信息 StringBuilder tempParams = new StringBuilder(); tempParams.append("Content-Disposition: form-data; name=\"" + name + "\"; filename=\"" + name + "\"; "); int pos = 0; int size = paramsMap.size(); for (String key : paramsMap.keySet()) { tempParams.append(String.format("%s=\"%s\"", key, paramsMap.get(key), "utf-8")); if (pos < size - 1) { tempParams.append("; "); } pos++; } tempParams.append("\r\n"); tempParams.append("Content-Type: application/octet-stream\r\n"); tempParams.append("\r\n"); String params = tempParams.toString(); requestStream.writeBytes(params); //发送文件数据 FileInputStream fileInput = new FileInputStream(file); int bytesRead; byte[] buffer = new byte[1024]; DataInputStream in = new DataInputStream(new FileInputStream(file)); while ((bytesRead = in.read(buffer)) != -1) { requestStream.write(buffer, 0, bytesRead); } requestStream.writeBytes("\r\n"); requestStream.flush(); requestStream.writeBytes("--" + "*****" + "--" + "\r\n"); requestStream.flush(); fileInput.close(); int statusCode = urlConn.getResponseCode(); if (statusCode == 200) { // 获取返回的数据 String result = streamToString(urlConn.getInputStream()); Log.e(TAG, "上传成功,result--->" + result); } else { Log.e(TAG, "上传失败"); } } catch (IOException e) { Log.e(TAG, e.toString()); } } }
在TestNet--app--src--main--AndroidMainifest.xml中添加
<uses-permission android:name="android.permission.INTERNET" />
参考文章:https://blog.csdn.net/qq_34317125/article/details/80533685