本文主要是介绍Mybatis打印全量sql,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
1. 实现Mybatis拦截器
@Intercepts({
@Signature(type = Executor.class, method = "update", args = {MappedStatement.class,
Object.class}),
@Signature(type = Executor.class, method = "query", args = {MappedStatement.class,
Object.class, RowBounds.class, ResultHandler.class})})
@SuppressWarnings({"unchecked", "rawtypes"})
public class MybatisInterceptor implements Interceptor {
private final Logger log = LoggerFactory.getLogger(MybatisInterceptor.class);
@Override
public Object intercept(Invocation invocation) throws Throwable {
try {
// 获取xml中的一个select/update/insert/delete节点,是一条SQL语句
MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[0];
Object parameter = null;
// 获取参数,if语句成立,表示sql语句有参数,参数格式是map形式
if (invocation.getArgs().length > 1) {
parameter = invocation.getArgs()[1];
System.out.println("parameter = " + parameter);
}
String sqlId = mappedStatement.getId(); // 获取到节点的id,即sql语句的id
System.out.println("sqlId = " + sqlId);
BoundSql boundSql = mappedStatement.getBoundSql(parameter); // BoundSql就是封装myBatis最终产生的sql类
Configuration configuration = mappedStatement.getConfiguration(); // 获取节点的配置
String sql = getSql(configuration, boundSql, sqlId); // 获取到最终的sql语句
System.out.println("sql = " + sql);
} catch (Exception e) {
e.printStackTrace();
}
// 执行完上面的任务后,不改变原有的sql执行过程
return invocation.proceed();
}
// 封装了一下sql语句,使得结果返回完整xml路径下的sql语句节点id + sql语句
public static String getSql(Configuration configuration, BoundSql boundSql, String sqlId) {
String sql = showSql(configuration, boundSql);
StringBuilder str = new StringBuilder(100);
str.append(sqlId);
str.append(":");
str.append(sql);
return str.toString();
}
// 如果参数是String,则添加单引号, 如果是日期,则转换为时间格式器并加单引号; 对参数是null和不是null的情况作了处理
private static String getParameterValue(Object obj) {
String value = null;
if (obj instanceof String) {
value = "'" + obj.toString() + "'";
} else if (obj instanceof Date) {
DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT,
DateFormat.DEFAULT, Locale.CHINA);
value = "'" + formatter.format(new Date()) + "'";
} else {
if (obj != null) {
value = obj.toString();
} else {
value = "";
}
}
return value;
}
// 进行?的替换
public static String showSql(Configuration configuration, BoundSql boundSql) {
// 获取参数
Object parameterObject = boundSql.getParameterObject();
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
// sql语句中多个空格都用一个空格代替
String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
if (CollectionUtils.isNotEmpty(parameterMappings) && parameterObject != null) {
// 获取类型处理器注册器,类型处理器的功能是进行java类型和数据库类型的转换
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
// 如果根据parameterObject.getClass()可以找到对应的类型,则替换
if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
sql = sql.replaceFirst("\\?",
Matcher.quoteReplacement(getParameterValue(parameterObject)));
} else {
// MetaObject主要是封装了originalObject对象,提供了get和set的方法用于获取和设置originalObject的属性值,主要支持对JavaBean、Collection、Map三种类型对象的操作
MetaObject metaObject = configuration.newMetaObject(parameterObject);
for (ParameterMapping parameterMapping : parameterMappings) {
String propertyName = parameterMapping.getProperty();
if (metaObject.hasGetter(propertyName)) {
Object obj = metaObject.getValue(propertyName);
sql = sql.replaceFirst("\\?",
Matcher.quoteReplacement(getParameterValue(obj)));
} else if (boundSql.hasAdditionalParameter(propertyName)) {
// 该分支是动态sql
Object obj = boundSql.getAdditionalParameter(propertyName);
sql = sql.replaceFirst("\\?",
Matcher.quoteReplacement(getParameterValue(obj)));
} else {
// 打印出缺失,提醒该参数缺失并防止错位
sql = sql.replaceFirst("\\?", "缺失");
}
}
}
}
return sql;
}
@Override
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}
@Override
public void setProperties(Properties properties) {
}
}
2. 添加拦截器
@Configuration
public class mybatisconfig {
@Bean
public MybatisInterceptor mybatisInterceptor() {
return new MybatisInterceptor();
}
}
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