使用动态代理实现用AOP对数据库进行操作

public class TransactionException extends RuntimeException {
private Throwable superException;
private String myMessage;

public TransactionException(Throwable throwable){
super(throwable);
this.superException = throwable;
}

public TransactionException(Throwable throwable,String message){
super(message,throwable);
this.superException = throwable;
this.myMessage = message;
}
/**
* @return Returns the myMessage.
*/
public String getMessage() {
return myMessage;
}
/**
* @return Returns the superException.
*/
public Throwable getSuperException() {
return superException;
}
/**
* @param myMessage The myMessage to set.
*/
public void setMyMessage(String message) {
this.myMessage = message;
}
/**
* @param superException The superException to set.
*/
public void setSuperException(Throwable superException) {
this.superException = superException;
}


}

l    DAO
import java.sql.Connection;
public class TestDao {
public void insertA(Connection con,String a,String b,……){
…………………………………………
一系列操作
…………………………………………
}

public String queryA(Connection con,…….){
…………………………………………
一系列操作
…………………………………………
}
public void updateA(Connection con,…….){
…………………………………………
一系列操作
…………………………………………
}
}
l    拦截器
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class TransactionInterceptor implements Interceptor {
public void before(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = (Connection) invInfo.getArgs()[0];
try {
conn.setAutoCommit(false);
} catch (SQLException e) {
throw new TransactionException(e);
}
}
}
public void after(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = (Connection) invInfo.getArgs()[0];
try {
conn.commit();
} catch (SQLException e) {
throw new TransactionException(e);
}finally{
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
throw new TransactionException(e,"Close Connection is failure!");
}
}
}
}
}
public void exceptionThrow(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = (Connection) invInfo.getArgs()[0];
try {
conn.rollback();
} catch (SQLException e) {
throw new TransactionException(e);
}finally{
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
throw new TransactionException(e,"Close Connection is failure!");
}
}
}
}
}

private List getNeedTransaction(){
List needTransactions = new ArrayList();
needTransactions.add("insert");
needTransactions.add("update");
return needTransactions;
}

private boolean isNeedTransactions(InvokeJniInfo invInfo){
String needTransaction = "";
List needTransactions = getNeedTransaction();
for(int i = 0;i             needTransaction = (String)needTransactions.get(i);
if(invInfo.getMethod().getName().startsWith(needTransaction)){
return true;
}
}
return false;
}
}

l    ConnectionUtil类：
import java.sql.Connection;
public final class ConnectionUtil {
private static ThreadLocal connections = new ThreadLocal();
public static Connection getConnection(){
Connection conn = null;
conn = (Connection) connections.get();
if(conn == null){
conn = getRealConnection();
connections.set(conn);
}
return conn;
}
public static void realseConnection(Connection conn){
connections.set(null);
}
private static Connection getRealConnection() {
实现自己获取连接的代码
return null;
}
}
l    DAO类
public class TestDao {
public void insertA(String a,String b){
Connection conn = getConnection();
…………………………………………
一系列操作
…………………………………………
}
public String queryA(Connection con,…….){
Connection conn = getConnection();
…………………………………………
一系列操作
…………………………………………
}
public void updateA(Connection con,…….){
Connection conn = getConnection();
…………………………………………
一系列操作
…………………………………………
}
private Connection getConnection(){
return ConnectionUtil.getConnection();
}

}
l    拦截器
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class TransactionInterceptor implements Interceptor {
public void before(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = getConnection();
try {
conn.setAutoCommit(false);
} catch (SQLException e) {
throw new TransactionException(e);
}
}
}
public void after(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = getConnection();
try {
conn.commit();
} catch (SQLException e) {
throw new TransactionException(e);
}finally{
if(conn != null){
try {
conn.close();
releaseConnection(conn);
} catch (SQLException e) {
throw new TransactionException(e,"Close Connection is failure!");
}
}
}
}
}
public void exceptionThrow(InvokeJniInfo invInfo) {
if(isNeedTransactions(invInfo)){
Connection conn = getConnection();
try {
conn.rollback();
} catch (SQLException e) {
throw new TransactionException(e);
}finally{
if(conn != null){
try {
conn.close();
releaseConnection(conn);
} catch (SQLException e) {
throw new TransactionException(e,"Close Connection is failure!");
}
}
}
}
}

private Connection getConnection(){
return ConnectionUtil.getConnection();
}

private void releaseConnection(Connection conn){
ConnectionUtil.releaseConnection(conn);
}
private List getNeedTransaction(){
List needTransactions = new ArrayList();
needTransactions.add("insert");
needTransactions.add("update");
return needTransactions;
}

private boolean isNeedTransactions(InvokeJniInfo invInfo){
String needTransaction = "";
List needTransactions = getNeedTransaction();
for(int i = 0;i             needTransaction = (String)needTransactions.get(i);
if(invInfo.getMethod().getName().startsWith(needTransaction)){
return true;
}
}
return false;
}
}