在Java中，你可以使用`HttpURLConnection`或第三方库（如Apache HttpClient）来发送HTTP请求。以下是使用`HttpURLConnection`编写四种基本HTTP请求（GET、POST、PUT、DELETE）的示例代码，并结合MySQL数据库操作。
### 1. 添加MySQL JDBC驱动依赖
首先，确保你已经将MySQL JDBC驱动添加到项目中。如果你使用的是Maven项目，可以在`pom.xml`中添加以下依赖：
```xml
mysql
mysql-connector-java
8.0.33
```
### 2. 编写HTTP请求和MySQL操作代码
```java
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class HttpAndMySQLExample {
// MySQL数据库连接信息
private static final String DB_URL = "jdbc:mysql://localhost:3306/your_database";
private static final String DB_USER = "your_username";
private static final String DB_PASSWORD = "your_password";
public static void main(String[] args) {
try {
// 发送GET请求
sendGetRequest("https://jsonplaceholder.typicode.com/posts/1");
// 发送POST请求
sendPostRequest("https://jsonplaceholder.typicode.com/posts", "{\"title\": \"foo\", \"body\": \"bar\", \"userId\": 1}");
// 发送PUT请求
sendPutRequest("https://jsonplaceholder.typicode.com/posts/1", "{\"id\": 1, \"title\": \"foo\", \"body\": \"bar\", \"userId\": 1}");
// 发送DELETE请求
sendDeleteRequest("https://jsonplaceholder.typicode.com/posts/1");
// 操作MySQL数据库
operateMySQL();
} catch (Exception e) {
e.printStackTrace();
}
}
// 发送GET请求
private static void sendGetRequest(String url) throws Exception {
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
System.out.println("GET Response Code: " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println("GET Response: " + response.toString());
}
// 发送POST请求
private static void sendPostRequest(String url, String jsonInputString) throws Exception {
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json; utf-8");
connection.setDoOutput(true);
try (OutputStream os = connection.getOutputStream()) {
byte[] input = jsonInputString.getBytes("utf-8");
os.write(input, 0, input.length);
}
int responseCode = connection.getResponseCode();
System.out.println("POST Response Code: " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
StringBuilder response = new StringBuilder();
String responseLine;
while ((responseLine = in.readLine()) != null) {
response.append(responseLine.trim());
}
System.out.println("POST Response: " + response.toString());
}
// 发送PUT请求
private static void sendPutRequest(String url, String jsonInputString) throws Exception {
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("PUT");
connection.setRequestProperty("Content-Type", "application/json; utf-8");
connection.setDoOutput(true);
try (OutputStream os = connection.getOutputStream()) {
byte[] input = jsonInputString.getBytes("utf-8");
os.write(input, 0, input.length);
}
int responseCode = connection.getResponseCode();
System.out.println("PUT Response Code: " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
StringBuilder response = new StringBuilder();
String responseLine;
while ((responseLine = in.readLine()) != null) {
response.append(responseLine.trim());
}
System.out.println("PUT Response: " + response.toString());
}
// 发送DELETE请求
private static void sendDeleteRequest(String url) throws Exception {
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("DELETE");
int responseCode = connection.getResponseCode();
System.out.println("DELETE Response Code: " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println("DELETE Response: " + response.toString());
}
// 操作MySQL数据库
private static void operateMySQL() {
try (Connection connection = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD)) {
// 查询数据
String query = "SELECT * FROM users";
PreparedStatement preparedStatement = connection.prepareStatement(query);
ResultSet resultSet = preparedStatement.executeQuery();
while (resultSet.next()) {
System.out.println("User ID: " + resultSet.getInt("id") + ", Name: " + resultSet.getString("name"));
}
// 插入数据
String insertQuery = "INSERT INTO users (name, email) VALUES (?, ?)";
preparedStatement = connection.prepareStatement(insertQuery);
preparedStatement.setString(1, "John Doe");
preparedStatement.setString(2, "john.doe@example.com");
preparedStatement.executeUpdate();
System.out.println("Data inserted successfully!");
// 更新数据
String updateQuery = "UPDATE users SET name = ? WHERE id = ?";
preparedStatement = connection.prepareStatement(updateQuery);
preparedStatement.setString(1, "Jane Doe");
preparedStatement.setInt(2, 1); // 假设ID为1的用户存在
preparedStatement.executeUpdate();
System.out.println("Data updated successfully!");
// 删除数据
String deleteQuery = "DELETE FROM users WHERE id = ?";
preparedStatement = connection.prepareStatement(deleteQuery);
preparedStatement.setInt(1, 1); // 假设ID为1的用户存在
preparedStatement.executeUpdate();
System.out.println("Data deleted successfully!");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
### 3. 代码说明
- **HTTP请求部分**：使用`HttpURLConnection`发送GET、POST、PUT、DELETE请求，并处理响应。
- **MySQL操作部分**：使用JDBC连接MySQL数据库，执行查询、插入、更新和删除操作。
- **异常处理**：捕获并打印异常信息，确保程序不会因为异常而崩溃。
### 4. 运行环境
- 确保MySQL数据库已启动，并且`your_database`、`your_username`、`your_password`等信息正确。
-
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