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提升查询MySQL性能

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This commit is contained in:
Tommy 2016-11-24 17:31:23 +08:00
parent b767d6c4a3
commit 3678fa69c3
3 changed files with 76 additions and 36 deletions
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5
APIJSON(Server)/src/main/java/zuo/biao/apijson/server/ServerGet2.java
View File

@ -43,6 +43,9 @@ public class ServerGet2 {
* "Comment[]":[{...}, ...]
*/
// SelectTable2.getInstance().close();
SelectTable3.getInstance().close();
return requestObject;
}
@ -366,7 +369,7 @@ public class ServerGet2 {
*/
private synchronized JSONObject getSQLObject(QueryConfig config) {
System.out.println("getSQLObject config = " + JSON.toJSONString(config));
return SelectTable2.select(config);//SelectTable3.getInstance().select(config);//
return SelectTable3.getInstance().select(config);//SelectTable2.getInstance().select(config);//
}
/**获取查询配置

62
APIJSON(Server)/src/main/java/zuo/biao/apijson/server/sql/SelectTable2.java
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@ -1,10 +1,6 @@
package zuo.biao.apijson.server.sql;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
@ -21,7 +17,22 @@ public class SelectTable2 {
// System.out.println(TAG + JSON.toJSONString(select("stu")));
}
public static Connection getConnection() throws Exception {
private static Connection connection;
private static Statement statement;
private static DatabaseMetaData metaData;
private SelectTable2() {
}
private static SelectTable2 instance;
public static synchronized SelectTable2 getInstance() {
if (instance == null) {
instance = new SelectTable2();
}
return instance;
}
public Connection getConnection() throws Exception {
//调用Class.forName()方法加载驱动程序
Class.forName("com.mysql.jdbc.Driver");
System.out.println(TAG + "成功加载MySQL驱动！");
@ -29,29 +40,44 @@ public class SelectTable2 {
return DriverManager.getConnection(url, "root", "199531tommy");
}
public static JSONObject select(String table) {
return select(new QueryConfig(table));
public void close() {
try {
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
public static JSONObject select(QueryConfig config) {
metaData = null;
statement = null;
}
public JSONObject select(QueryConfig config) {
if (config == null || StringUtil.isNotEmpty(config.getTable(), true) == false) {
System.out.println(TAG + "select config==null||StringUtil.isNotEmpty(config.getTable(), true)==false>>return null;");
return null;
}
final String sql = config.getSQL();
try{
Connection conn = getConnection();
Statement stmt = conn.createStatement(); //创建Statement对象
System.out.println(TAG + "成功连接到数据库！");
List<String> list = getColumnList(config.getTable(), conn.getMetaData());
if (connection == null || connection.isClosed()) {
System.out.println(TAG + "select connection " + (connection == null ? " = null" : ("isClosed = " + connection.isClosed()))) ;
connection = getConnection();
statement = connection.createStatement(); //创建Statement对象
metaData = connection.getMetaData();
}
List<String> list = getColumnList(config.getTable());
if (list == null || list.isEmpty()) {
return null;
}
String sql = "select * from " + config.getTable() + config.getWhereString() + config.getLimitString(); //要执行的SQL
System.out.println(TAG + "select sql = " + sql);
ResultSet rs = stmt.executeQuery(sql);//创建数据对象
ResultSet rs = statement.executeQuery(sql);//创建数据对象
JSONObject object = null;//new JSONObject();//null;
int position = -1;
@ -74,8 +100,6 @@ public class SelectTable2 {
}
rs.close();
stmt.close();
conn.close();
return object;
} catch(Exception e) {
@ -90,11 +114,11 @@ public class SelectTable2 {
* @param table
* @return
*/
public static List<String> getColumnList(String table, DatabaseMetaData meta) {
public List<String> getColumnList(String table) {
List<String> list = new ArrayList<String>();
ResultSet rs;
try {
rs = meta.getColumns("sys", null, table, "%");
rs = metaData.getColumns("sys", null, table, "%");
while (rs.next()) {
System.out.println(TAG + rs.getString(4));
list.add(rs.getString(4));

41
APIJSON(Server)/src/main/java/zuo/biao/apijson/server/sql/SelectTable3.java
View File

@ -1,10 +1,6 @@
package zuo.biao.apijson.server.sql;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
@ -20,7 +16,7 @@ public class SelectTable3 {
private Map<String, List<JSONObject>> cacheMap;
private SelectTable3() {
cacheMap = new HashMap<String, List<JSONObject>>();
}
private static SelectTable3 instance;
@ -59,6 +55,20 @@ public class SelectTable3 {
return list == null || position < 0 || position >= list.size() ? null : list.get(position);
}
private static Connection connection;
private static Statement statement;
private static DatabaseMetaData metaData;
public void close() {
try {
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
metaData = null;
statement = null;
cacheMap = null;
}
public JSONObject select(QueryConfig config) {
if (config == null || StringUtil.isNotEmpty(config.getTable(), true) == false) {
@ -68,17 +78,22 @@ public class SelectTable3 {
final String sql = config.getSQL();
final int position = config.getPosition();
if (cacheMap == null) {
cacheMap = new HashMap<String, List<JSONObject>>();
}
JSONObject object = getFromCache(sql, position);
if (object != null) {
return object;
}
try{
Connection conn = getConnection();
Statement stmt = conn.createStatement(); //创建Statement对象
System.out.println(TAG + "成功连接到数据库！");
List<String> list = getColumnList(config.getTable(), conn.getMetaData());
if (connection == null || connection.isClosed()) {
System.out.println(TAG + "select connection " + (connection == null ? " = null" : ("isClosed = " + connection.isClosed()))) ;
connection = getConnection();
statement = connection.createStatement(); //创建Statement对象
metaData = connection.getMetaData();
}
List<String> list = getColumnList(config.getTable(), metaData);
if (list == null || list.isEmpty()) {
return null;
}
@ -86,7 +101,7 @@ public class SelectTable3 {
System.out.println(TAG + "select sql = " + sql);
ResultSet rs = stmt.executeQuery(sql);//创建数据对象
ResultSet rs = statement.executeQuery(sql);//创建数据对象
List<JSONObject> resultList = new ArrayList<JSONObject>();
while (rs.next()){
@ -104,8 +119,6 @@ public class SelectTable3 {
resultList.add(object);
}
rs.close();
stmt.close();
conn.close();
//从缓存存取，避免 too many connections崩溃
if (position < config.getLimit() - 1) {