java读取配置文件例子(多线程更新表数据)
config.properties
# config.properties
db.url=jdbc:mysql://192.168.1.14:3306/db_admin?useSSL=false
db.username=root
db.password=123456
存放路径
LoadConfig.java
package org.hxl.rds;
import java.io.InputStream;
import java.util.Properties;
public class LoadConfig {
private static String url;
private static String username;
private static String password;
public LoadConfig(){
LoadConfigData();
}
public static void LoadConfigData() {
try (InputStream input = LoadConfig.class.getClassLoader()
.getResourceAsStream("config.properties")) {
Properties prop = new Properties();
if (input == null) {
throw new RuntimeException("配置文件 db.properties 未找到");
}
prop.load(input);
url = prop.getProperty("db.url");
username = prop.getProperty("db.username");
password = prop.getProperty("db.password");
} catch (Exception e) {
throw new RuntimeException("配置文件加载失败", e);
}
}
public String getDbUrl() {
return url;
}
public String getDbUsername() {
return username;
}
public String getDbPassword() {
return password;
}
}
DatabaseConnectionPool.java
package org.hxl.rds;
import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import java.sql.Connection;
import java.sql.SQLException;
public class DatabaseConnectionPool {
private static final int THREAD_POOL_SIZE = 16; // 建议CPU核心数*2
private static HikariDataSource dataSource;
static LoadConfig lcdata = new LoadConfig();
static String url = lcdata.getDbUrl();
static String username = lcdata.getDbUsername();
static String password = lcdata.getDbPassword();
static {
HikariConfig config = new HikariConfig();
//config.setJdbcUrl("jdbc:mysql://192.168.1.14:3306/db_admin?useSSL=false");
//config.setUsername("root");
//config.setPassword("yeemiao1117");
config.setJdbcUrl(url);
config.setUsername(username);
config.setPassword(password);
config.setMaximumPoolSize(THREAD_POOL_SIZE + 5); // 预留额外连接
config.addDataSourceProperty("cachePrepStmts", "true");
config.addDataSourceProperty("prepStmtCacheSize", "250");
config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
dataSource = new HikariDataSource(config);
}
public static Connection getConnection() throws SQLException {
return dataSource.getConnection();
}
}
多线程代码处理
MassiveDataProcessor.java
package org.hxl.rds;
import java.sql.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class MassiveDataProcessor {
private static final String TABLE_NAME = "user";
//线程与分片配置
private static final int THREAD_POOL_SIZE = 16; // 建议CPU核心数*2
private static final long BATCH_SIZE = 5000; // 每批次处理量
private static final int UPDATE_BATCH_SIZE = 1000; // 批量更新大小
// 获取主键范围
private static long[] getIdRange() throws SQLException {
long IdRange[] = new long[2];
try {
Connection conn = DatabaseConnectionPool.getConnection();
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(
"SELECT MIN(id) as min_id, MAX(id) as max_id FROM " + TABLE_NAME);
if (rs.next()) {
IdRange[0] = rs.getLong("min_id");
IdRange[1] = rs.getLong("max_id");
//return new long[]{rs.getLong("min_id"), rs.getLong("max_id")};
}
} catch (SQLException e) {
throw new RuntimeException("No data in table");
}
return IdRange;
}
// 数据处理任务
static class DataProcessTask implements Runnable {
private final long startId;
private final long endId;
public DataProcessTask(long startId, long endId) throws SQLException {
this.startId = startId;
this.endId = endId;
}
@Override
public void run() {
Connection conn = null;
try {
conn = DatabaseConnectionPool.getConnection();
} catch (SQLException e) {
throw new RuntimeException(e);
}
try {
// 1. 分页查询数据
String selectSQL = "SELECT id, name FROM " + TABLE_NAME +
" WHERE id >= ? AND id<= ? ORDER BY id";
String updateSQL = "UPDATE " + TABLE_NAME +
" SET name = ? WHERE id = ?";
conn.setAutoCommit(false); // 开启事务
PreparedStatement selectStmt = conn.prepareStatement(
selectSQL, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
selectStmt.setLong(1, startId);
selectStmt.setLong(2, endId);
selectStmt.setFetchSize(1000); // 流式读取防止OOM
ResultSet rs = selectStmt.executeQuery();
PreparedStatement updateStmt = conn.prepareStatement(updateSQL);
int batchCount = 0;
while (rs.next()) {
long id = rs.getLong("id");
String data = rs.getString("name");
// 3. 业务处理（示例：转换为大写）
String processedData = processData(data);
// 4. 设置更新参数
updateStmt.setString(1, processedData);
updateStmt.setLong(2, id);
updateStmt.addBatch();
// 5. 批量提交
if (++batchCount % UPDATE_BATCH_SIZE == 0) {
updateStmt.executeBatch();
conn.commit();
System.out.println("commit ok!");
}
}
// 提交剩余批次
updateStmt.executeBatch();
conn.commit();
} catch (SQLException e) {
throw new RuntimeException(e);
} finally {
try {
conn.close();
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
// 示例数据处理函数（需替换实际业务逻辑）
private String processData(String data) {
// 实际业务处理逻辑
//return data != null ? data.toUpperCase() : null;
return data != null ? "VVVV" : null;
}
}
public static void main(String[] args) {
Date startDate = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String startTime = sdf.format(startDate);
System.out.println("开始时间：" + startTime);
try {
// 1. 获取主键范围
long[] idRange = getIdRange();
long minId = idRange[0];
long maxId = idRange[1];
System.out.printf("ID Range: %d - %d%n", minId, maxId);
// 2. 计算分片数量
long totalRecords = maxId - minId + 1;
int shards = (int) Math.ceil((double) totalRecords / BATCH_SIZE);
System.out.println(shards);
// 3. 创建线程池
ExecutorService executor = Executors.newFixedThreadPool(THREAD_POOL_SIZE);
// 4. 提交分片处理任务
for (int i = 0; i < shards; i++) {
long startId = minId + (i * BATCH_SIZE);
long endId = Math.min(startId + BATCH_SIZE - 1, maxId);
System.out.println("startId=" + startId + ",endId=" + endId);
executor.submit(new DataProcessTask(startId, endId));
//System.out.println(executor.toString());
}
// 5. 优雅关闭
executor.shutdown();
executor.awaitTermination(1, TimeUnit.HOURS);
} catch (Exception e) {
e.printStackTrace();
}
Date endDate = new Date();
String endTime = sdf.format(endDate);
System.out.println("结束时间：" + endTime);
}
}
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