增加源码分析-insert()
---------------------------------------------------------------------
public int insert(String statement, Object parameter) { //statement就是传进来的要调用xml定义的哪个sql语句，parameter就是调用语句需要传进来的参数对象
return update(statement, parameter);
}
---------------------------------------------------------------------
进入到update方法中
public int update(String statement, Object parameter) {
try {
dirty = true; //
MappedStatement ms = configuration.getMappedStatement(statement); //configuration通过传进来的参数，获取对应的映射statement
return executor.update(ms, wrapCollection(parameter)); //executor是个代理对象
} catch (Exception e) {
throw ExceptionFactory.wrapException("Error updating database. Cause: " + e, e);
} finally {
ErrorContext.instance().reset();
}
}
---------------------------------------------------------------
进入到invoke方法中
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { //参数中的method是Executor.update
try {
//获取声明的方法集[Executor.query],这个集合是自己在mybatis配置文件plugin节点下定义的要拦截的方法集
Set<Method> methods = signatureMap.get(method.getDeclaringClass());
if (methods != null && methods.contains(method)) { // methods.contains(method)==false
return interceptor.intercept(new Invocation(target, method, args));
}
//target是CachingExecutor类型的，其中有两个参数SimpleExecutor的delegate和TransactionalCacheManager类型的tcm
//args是Object数组，[0]=MappedStatement,[1]=Employee(上面update方法传进来的参数)
return method.invoke(target, args); //交给target所指定的方法继续执行程序
} catch (Exception e) {
throw ExceptionUtil.unwrapThrowable(e);
}
}
----------------------------------------------------------------
public int update(MappedStatement ms, Object parameterObject) throws SQLException {
flushCacheIfRequired(ms); //如果有缓存，则清除。
return delegate.update(ms, parameterObject);
}
-----------------------------------------------------------
public int update(MappedStatement ms, Object parameter) throws SQLException {
ErrorContext.instance().resource(ms.getResource()).activity("executing an update").object(ms.getId());
if (closed) throw new ExecutorException("Executor was closed.");
clearLocalCache(); //清除本地缓存
return doUpdate(ms, parameter);
}
---------------------------------------------------------------------------------------------------------
public int doUpdate(MappedStatement ms, Object parameter) throws SQLException {
Statement stmt = null;
try {
Configuration configuration = ms.getConfiguration();
StatementHandler handler = configuration.newStatementHandler(this, ms, parameter, RowBounds.DEFAULT, null, null); //这里新建一个statement处理程序
stmt = prepareStatement(handler, ms.getStatementLog()); //statement准备阶段，获取到有关数据库的信息等
return handler.update(stmt);
} finally {
closeStatement(stmt);
}
}
------------------------------newStatementHandler具体执行过程-------------------------------------------------------------------------------------------------------
public StatementHandler newStatementHandler(Executor executor, MappedStatement mappedStatement, Object parameterObject, RowBounds
rowBounds, ResultHandler resultHandler, BoundSql boundSql) {
StatementHandler statementHandler = new RoutingStatementHandler(executor, mappedStatement, parameterObject, rowBounds, resultHandler, boundSql);
statementHandler = (StatementHandler) interceptorChain.pluginAll(statementHandler);
return statementHandler;
}
------------------------
public RoutingStatementHandler(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) {
switch (ms.getStatementType()) { //PREPARED(默认)
case STATEMENT:
delegate = new SimpleStatementHandler(executor, ms, parameter, rowBounds, resultHandler, boundSql);
break;
case PREPARED:
delegate = new PreparedStatementHandler(executor, ms, parameter, rowBounds, resultHandler, boundSql);
break;
case CALLABLE:
delegate = new CallableStatementHandler(executor, ms, parameter, rowBounds, resultHandler, boundSql);
break;
default:
throw new ExecutorException("Unknown statement type: " + ms.getStatementType());
}
}
---------------------
public PreparedStatementHandler(Executor executor, MappedStatement mappedStatement, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) {
super(executor, mappedStatement, parameter, rowBounds, resultHandler, boundSql);
}
---------------------------
protected BaseStatementHandler(Executor executor, MappedStatement mappedStatement, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) {
this.configuration = mappedStatement.getConfiguration();
this.executor = executor;
this.mappedStatement = mappedStatement;
this.rowBounds = rowBounds;
this.typeHandlerRegistry = configuration.getTypeHandlerRegistry();
this.objectFactory = configuration.getObjectFactory();
if (boundSql == null) { // issue #435, get the key before calculating the statement
generateKeys(parameterObject);
boundSql = mappedStatement.getBoundSql(parameterObject); //获取boundSql
}
this.boundSql = boundSql;
this.parameterHandler = configuration.newParameterHandler(mappedStatement, parameterObject, boundSql); //参数处理器
this.resultSetHandler = configuration.newResultSetHandler(executor, mappedStatement, rowBounds, parameterHandler, resultHandler, boundSql);//结果处理器
}
------------------真正执行插入的核心代码在PreparedStatementHandler类中------------------------
public int update(Statement statement) throws SQLException {
PreparedStatement ps = (PreparedStatement) statement;
ps.execute(); //执行插入
int rows = ps.getUpdateCount();
Object parameterObject = boundSql.getParameterObject();
KeyGenerator keyGenerator = mappedStatement.getKeyGenerator();
keyGenerator.processAfter(executor, mappedStatement, ps, parameterObject);
return rows; //返回执行的结果
}
-----------------------------------------------------------------------------------------------------
修改源码分析--update()同增加操作
删除源码分析--delete()同update()操作
public int delete(String statement, Object parameter) {
return update(statement, parameter);
}