题目:连接数据库,取出数据。
用到的类:
Connection:连接数据库
Statement:The object used for executing a static SQL statement and returning the results it produces.
ResultSet:A table of data representing a database result set, which is usually generated by executing a statement that queries the database.
package everyDay;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
public class GetData {
@Test
public void mysqlconnection() {
try {
String url = "jdbc:mysql://10.255.255.148:3306/testresults";
String user = "user";
String password = "pwd";
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
//conn.setAutoCommit(false);
String sql = "select timeStamp, elapsed from cpuInfo order by timeStamp";
ResultSet rs = stmt.executeQuery(sql);
//conn.commit();
//conn.setAutoCommit(true);
List<String> list = new ArrayList<String>();
while (rs.next()) {
list.add(rs.getString(1));//添加其中一列
}
if (list != null && list.size() > 0) {// 如果list中存入了数据,转化为数组
String[] arr = new String[list.size()];// 创建一个和list长度一样的数组
for (int i = 0; i < list.size(); i++) {
arr[i] = list.get(i);// 数组赋值。
}
// 输出数组
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i]);
}
}
} catch (Exception e) {
// TODO: handle exception
}
}
}