org.apache.ibatis.executor.parameter.ParameterHandler Java Examples

/**
 * TODO：
 * @param invocation
 * @return
 * @throws Throwable
 * @author zjh
 * @date 2017-2-15
 */
@Override
public Object intercept(Invocation invocation) throws Throwable {
	//通过invocation获取代理的目标对象
	Object target = invocation.getTarget();
	//暂时ResultSetHandler只有FastResultSetHandler这一种实现
	if (target instanceof DefaultResultSetHandler) {
		DefaultResultSetHandler resultSetHandler = (DefaultResultSetHandler) target;
		//利用反射获取到FastResultSetHandler的ParameterHandler属性，从而获取到ParameterObject；
		ParameterHandler parameterHandler = (ParameterHandler) ReflectUtil.getFieldValue(resultSetHandler,
				"parameterHandler");
		Object parameterObj = parameterHandler.getParameterObject();
		//判断ParameterObj是否是我们定义的MapParam，如果是则进行自己的处理逻辑
		if (parameterObj instanceof MapParam) {//拦截到了
			MapParam mapParam = (MapParam) parameterObj;
			//获取到当前的Statement
			Statement stmt = (Statement) invocation.getArgs()[0];
			//通过Statement获取到当前的结果集，对其进行处理，并返回对应的处理结果
			return handleResultSet(stmt.getResultSet(), mapParam);
		}
	}
	
	
	
	//如果没有进行拦截处理，则执行默认逻辑
	return invocation.proceed();
}
 

@Override
    public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object o, BoundSql boundSql) {
        logger.trace("createParameterHandler({}, Object: {}, BoundSql:{}", mappedStatement, o, boundSql.getSql());
        logger.trace("Object: class:{}, isMap:{}", o.getClass().getName(), o instanceof Map);
//        logger.trace("")
        logger.trace("boundSql: class: {}, sql: {}, getParameterMappings: {}, getParameterObject:{}",
                boundSql.getClass().getName(), boundSql.getSql(), boundSql.getParameterMappings(), boundSql.getParameterObject());
        return super.createParameterHandler(mappedStatement, o, boundSql);
    }
 

public DefaultResultSetHandler(Executor executor, MappedStatement mappedStatement, ParameterHandler parameterHandler, ResultHandler resultHandler, BoundSql boundSql,
    RowBounds rowBounds) {
  this.executor = executor;
  this.configuration = mappedStatement.getConfiguration();
  this.mappedStatement = mappedStatement;
  this.rowBounds = rowBounds;
  this.parameterHandler = parameterHandler;
  this.boundSql = boundSql;
  this.typeHandlerRegistry = configuration.getTypeHandlerRegistry();
  this.objectFactory = configuration.getObjectFactory();
  this.resultHandler = resultHandler;
}
 

public DefaultResultSetHandler(Executor executor, MappedStatement mappedStatement, ParameterHandler parameterHandler, ResultHandler resultHandler, BoundSql boundSql,
    RowBounds rowBounds) {
  this.executor = executor;
  this.configuration = mappedStatement.getConfiguration();
  this.mappedStatement = mappedStatement;
  this.rowBounds = rowBounds;
  this.parameterHandler = parameterHandler;
  this.boundSql = boundSql;
  this.typeHandlerRegistry = configuration.getTypeHandlerRegistry();
  this.objectFactory = configuration.getObjectFactory();
  this.resultHandler = resultHandler;
}
 

private List<String> getParameters(MappedStatement ms, Object parameterObject, BoundSql boundSql) throws SQLException {
    // DefaultParameterHandler is the only implementation of parameterHandler interface currently. it may be changed later.
    // need additional codes to find a appropriate implementation in that case.
    ParameterHandler parameterHandler = new DefaultParameterHandler(ms, parameterObject, boundSql);
    PreparedStatementParameterLogger parameterLogger = new PreparedStatementParameterLogger();
    parameterHandler.setParameters(parameterLogger);
    return parameterLogger.getParameters();
}
 

public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
  return new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
}
 

/**
 * Contrary to the spec, some drivers require case-sensitive column names when getting result.
 * 
 * @see <a href="http://code.google.com/p/mybatis/issues/detail?id=557">Issue 557</a>
 */
@Test
public void shouldRetainColumnNameCase() throws Exception {

  final Configuration config = new Configuration();
  final TypeHandlerRegistry registry = config.getTypeHandlerRegistry();
  final MappedStatement ms = new MappedStatement.Builder(config, "testSelect", new StaticSqlSource(config, "some select statement"), SqlCommandType.SELECT).resultMaps(
      new ArrayList<ResultMap>() {
        {
          add(new ResultMap.Builder(config, "testMap", HashMap.class, new ArrayList<ResultMapping>() {
            {
              add(new ResultMapping.Builder(config, "cOlUmN1", "CoLuMn1", registry.getTypeHandler(Integer.class)).build());
            }
          }).build());
        }
      }).build();

  final Executor executor = null;
  final ParameterHandler parameterHandler = null;
  final ResultHandler resultHandler = null;
  final BoundSql boundSql = null;
  final RowBounds rowBounds = new RowBounds(0, 100);
  final DefaultResultSetHandler fastResultSetHandler = new DefaultResultSetHandler(executor, ms, parameterHandler, resultHandler, boundSql, rowBounds);

  when(stmt.getResultSet()).thenReturn(rs);
  when(rs.getMetaData()).thenReturn(rsmd);
  when(rs.getType()).thenReturn(ResultSet.TYPE_FORWARD_ONLY);
  when(rs.next()).thenReturn(true).thenReturn(false);
  when(rs.getInt("CoLuMn1")).thenReturn(100);
  when(rs.wasNull()).thenReturn(false);
  when(rsmd.getColumnCount()).thenReturn(1);
  when(rsmd.getColumnLabel(1)).thenReturn("CoLuMn1");
  when(rsmd.getColumnType(1)).thenReturn(Types.INTEGER);
  when(rsmd.getColumnClassName(1)).thenReturn(Integer.class.getCanonicalName());
  when(stmt.getConnection()).thenReturn(conn);
  when(conn.getMetaData()).thenReturn(dbmd);
  when(dbmd.supportsMultipleResultSets()).thenReturn(false); // for simplicity.

  final List<Object> results = fastResultSetHandler.handleResultSets(stmt);
  assertEquals(1, results.size());
  assertEquals(Integer.valueOf(100), ((HashMap) results.get(0)).get("cOlUmN1"));
}
 

public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
  return new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
}
 

@Override
public ParameterHandler getParameterHandler() {
  return parameterHandler;
}
 

@Override
public ParameterHandler getParameterHandler() {
  return delegate.getParameterHandler();
}
 

@Override
 public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
   //返回默认的参数处理器
return new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
 }
 

/**
 * Contrary to the spec, some drivers require case-sensitive column names when getting result.
 * 
 * @see <a href="http://code.google.com/p/mybatis/issues/detail?id=557">Issue 557</a>
 */
@Test
public void shouldRetainColumnNameCase() throws Exception {

  final Configuration config = new Configuration();
  final TypeHandlerRegistry registry = config.getTypeHandlerRegistry();
  final MappedStatement ms = new MappedStatement.Builder(config, "testSelect", new StaticSqlSource(config, "some select statement"), SqlCommandType.SELECT).resultMaps(
      new ArrayList<ResultMap>() {
        {
          add(new ResultMap.Builder(config, "testMap", HashMap.class, new ArrayList<ResultMapping>() {
            {
              add(new ResultMapping.Builder(config, "cOlUmN1", "CoLuMn1", registry.getTypeHandler(Integer.class)).build());
            }
          }).build());
        }
      }).build();

  final Executor executor = null;
  final ParameterHandler parameterHandler = null;
  final ResultHandler resultHandler = null;
  final BoundSql boundSql = null;
  final RowBounds rowBounds = new RowBounds(0, 100);
  final DefaultResultSetHandler fastResultSetHandler = new DefaultResultSetHandler(executor, ms, parameterHandler, resultHandler, boundSql, rowBounds);

  when(stmt.getResultSet()).thenReturn(rs);
  when(rs.getMetaData()).thenReturn(rsmd);
  when(rs.getType()).thenReturn(ResultSet.TYPE_FORWARD_ONLY);
  when(rs.next()).thenReturn(true).thenReturn(false);
  when(rs.getInt("CoLuMn1")).thenReturn(100);
  when(rs.wasNull()).thenReturn(false);
  when(rsmd.getColumnCount()).thenReturn(1);
  when(rsmd.getColumnLabel(1)).thenReturn("CoLuMn1");
  when(rsmd.getColumnType(1)).thenReturn(Types.INTEGER);
  when(rsmd.getColumnClassName(1)).thenReturn(Integer.class.getCanonicalName());
  when(stmt.getConnection()).thenReturn(conn);
  when(conn.getMetaData()).thenReturn(dbmd);
  when(dbmd.supportsMultipleResultSets()).thenReturn(false); // for simplicity.

  final List<Object> results = fastResultSetHandler.handleResultSets(stmt);
  assertEquals(1, results.size());
  assertEquals(Integer.valueOf(100), ((HashMap) results.get(0)).get("cOlUmN1"));
}
 

@Override
public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
    return new CustomMybatisPlusParameterHandler(mappedStatement, parameterObject, boundSql);
}
 

@Override
public ParameterHandler getParameterHandler() {
  return parameterHandler;
}
 

@Override
public ParameterHandler getParameterHandler() {
  return delegate.getParameterHandler();
}
 

@Override
 public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
   //返回默认的参数处理器
return new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
 }
 

@Override
public ParameterHandler createParameterHandler(final MappedStatement mappedStatement, final Object parameterObject, final BoundSql boundSql) {
    return new CustomMybatisParameterHandler(mappedStatement, parameterObject, boundSql);
}
 

/**
 * Creates a {@link ParameterHandler} that passes the actual parameters to the the JDBC statement.
 * 
 * @author Frank D. Martinez [mnesarco]
 * @see DefaultParameterHandler
 * @param mappedStatement The mapped statement that is being executed
 * @param parameterObject The input parameter object (can be null) 
 * @param boundSql The resulting SQL once the dynamic language has been executed.
 * @return
 */
//创建参数处理器
ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql);
 

/**
 * Creates a {@link ParameterHandler} that passes the actual parameters to the the JDBC statement.
 * 
 * @author Frank D. Martinez [mnesarco]
 * @see DefaultParameterHandler
 * @param mappedStatement The mapped statement that is being executed
 * @param parameterObject The input parameter object (can be null) 
 * @param boundSql The resulting SQL once the dynamic language has been executed.
 * @return
 */
//创建参数处理器
ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql);
 

/**
 * 代入参数值
 * 
 * @param ps
 * @param mappedStatement
 * @param boundSql
 * @param parameterObject
 * @throws SQLException
 */
private void setParameters(PreparedStatement ps, MappedStatement mappedStatement, BoundSql boundSql,
		Object parameterObject) throws SQLException {
	ParameterHandler parameterHandler = new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
	parameterHandler.setParameters(ps);
}
 

ParameterHandler getParameterHandler(); 

ParameterHandler getParameterHandler();