mybatis自定义插件动态修改sql语句

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.mapping.SqlSource;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.springframework.beans.factory.annotation.Value;

import java.util.Properties;

/**
* code by me
* <p>
* Data:2017/8/10 Time:11:28
* User:lbh
*/
@Intercepts
({
@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}),
})
public class FDNSqlInterceptor implements Interceptor {
private static Log logger = LogFactory.getLog(FDNSqlInterceptor.class);

@Value("${fdn.open}")
private boolean fdnOpen;

static int MAPPED_STATEMENT_INDEX = 0;// 这是对应上面的args的序号
static int PARAMETER_INDEX = 1;
static int ROWBOUNDS_INDEX = 2;
static int RESULT_HANDLER_INDEX = 3;
@Override
public Object intercept(Invocation invocation) throws Throwable {
if(!fdnOpen){
return invocation.proceed();
}
final Object[] queryArgs = invocation.getArgs();
final MappedStatement mappedStatement = (MappedStatement) queryArgs[MAPPED_STATEMENT_INDEX];
final Object parameter = queryArgs[PARAMETER_INDEX];
final BoundSql boundSql = mappedStatement.getBoundSql(parameter);

String sql = boundSql.getSql();
if(sql.contains("xx_pro")){
sql = sql.replace("xx_pro","xx_pro_fdn");
}

// 重新new一个查询语句对像
BoundSql newBoundSql = new BoundSql(mappedStatement.getConfiguration(), sql, boundSql.getParameterMappings(), boundSql.getParameterObject());
// 把新的查询放到statement里
MappedStatement newMs = copyFromMappedStatement(mappedStatement, new BoundSqlSqlSource(newBoundSql));
for (ParameterMapping mapping : boundSql.getParameterMappings()) {
String prop = mapping.getProperty();
if (boundSql.hasAdditionalParameter(prop)) {
newBoundSql.setAdditionalParameter(prop, boundSql.getAdditionalParameter(prop));
}
}
queryArgs[MAPPED_STATEMENT_INDEX] = newMs;
return invocation.proceed();
}

@Override
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}

@Override
public void setProperties(Properties properties) {

}

private MappedStatement copyFromMappedStatement(MappedStatement ms, SqlSource newSqlSource) {
MappedStatement.Builder builder = new MappedStatement.Builder(ms.getConfiguration(), ms.getId(), newSqlSource, ms.getSqlCommandType());
builder.resource(ms.getResource());
builder.fetchSize(ms.getFetchSize());
builder.statementType(ms.getStatementType());
builder.keyGenerator(ms.getKeyGenerator());
if (ms.getKeyProperties() != null && ms.getKeyProperties().length > 0) {
builder.keyProperty(ms.getKeyProperties()[0]);
}
builder.timeout(ms.getTimeout());
builder.parameterMap(ms.getParameterMap());
builder.resultMaps(ms.getResultMaps());
builder.resultSetType(ms.getResultSetType());
builder.cache(ms.getCache());
builder.flushCacheRequired(ms.isFlushCacheRequired());
builder.useCache(ms.isUseCache());
return builder.build();
}

public static class BoundSqlSqlSource implements SqlSource {
private BoundSql boundSql;
public BoundSqlSqlSource(BoundSql boundSql) {
this.boundSql = boundSql;
}
public BoundSql getBoundSql(Object parameterObject) {
return boundSql;
}
}
}

　　<plugins>
<plugin interceptor="xx.interceptor.FDNSqlInterceptor"></plugin>
</plugins>