mybatis 插件: 打印 sql 及其执行时间实现方法

/**
 * Sql执行时间记录拦截器 
 */
@Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),
 @Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),
 @Signature(type = StatementHandler.class, method = "batch", args = { Statement.class })})
public class SqlCostInterceptor implements Interceptor {
 
 @Override
 public Object intercept(Invocation invocation) throws Throwable {
  Object target = invocation.getTarget();
   
  long startTime = System.currentTimeMillis();
  StatementHandler statementHandler = (StatementHandler)target;
  try {
   return invocation.proceed();
  } finally {
   long endTime = System.currentTimeMillis();
   long sqlCost = endTime - startTime;
    
   BoundSql boundSql = statementHandler.getBoundSql();
   String sql = boundSql.getSql();
   Object parameterObject = boundSql.getParameterObject();
   List<ParameterMapping> parameterMappingList = boundSql.getParameterMappings();
    
   // 格式化Sql语句，去除换行符，替换参数
   sql = formatSql(sql, parameterObject, parameterMappingList);
    
   System.out.println("SQL：[" + sql + "]执行耗时[" + sqlCost + "ms]");
  }
 }
 
 @Override
 public Object plugin(Object target) {
  return Plugin.wrap(target, this);
 }
 
 @Override
 public void setProperties(Properties properties) {
   
 }
  
 @SuppressWarnings("unchecked")
 private String formatSql(String sql, Object parameterObject, List<ParameterMapping> parameterMappingList) {
  // 输入sql字符串空判断
  if (sql == null || sql.length() == 0) {
   return "";
  }
   
  // 美化sql
  sql = beautifySql(sql);
   
  // 不传参数的场景，直接把Sql美化一下返回出去
  if (parameterObject == null || parameterMappingList == null || parameterMappingList.size() == 0) {
   return sql;
  }
   
  // 定义一个没有替换过占位符的sql，用于出异常时返回
  String sqlWithoutReplacePlaceholder = sql;
   
  try {
   if (parameterMappingList != null) {
    Class<?> parameterObjectClass = parameterObject.getClass();
 
    // 如果参数是StrictMap且Value类型为Collection，获取key="list"的属性，这里主要是为了处理<foreach>循环时传入List这种参数的占位符替换
    // 例如select * from xxx where id in <foreach collection="list">...</foreach>
    if (isStrictMap(parameterObjectClass)) {
     StrictMap<Collection<?>> strictMap = (StrictMap<Collection<?>>)parameterObject;
      
     if (isList(strictMap.get("list").getClass())) {
      sql = handleListParameter(sql, strictMap.get("list"));
     }
    } else if (isMap(parameterObjectClass)) {
     // 如果参数是Map则直接强转，通过map.get(key)方法获取真正的属性值
     // 这里主要是为了处理<insert>、<delete>、<update>、<select>时传入parameterType为map的场景
     Map<?, ?> paramMap = (Map<?, ?>) parameterObject;
     sql = handleMapParameter(sql, paramMap, parameterMappingList);
    } else {
     // 通用场景，比如传的是一个自定义的对象或者八种基本数据类型之一或者String
     sql = handleCommonParameter(sql, parameterMappingList, parameterObjectClass, parameterObject);
    }
   }
  } catch (Exception e) {
   // 占位符替换过程中出现异常，则返回没有替换过占位符但是格式美化过的sql，这样至少保证sql语句比BoundSql中的sql更好看
   return sqlWithoutReplacePlaceholder;
  }
   
  return sql;
 }
  
 /**
  * 美化Sql
  */
 private String beautifySql(String sql) {
  sql = sql.replace("\n", "").replace("\t", "").replace(" ", " ").replace("( ", "(").replace(" )", ")").replace(" ,", ",");
   
  return sql;
 }
  
 /**
  * 处理参数为List的场景
  */
 private String handleListParameter(String sql, Collection<?> col) {
  if (col != null && col.size() != 0) {
   for (Object obj : col) {
    String value = null;
    Class<?> objClass = obj.getClass();
     
    // 只处理基本数据类型、基本数据类型的包装类、String这三种
    // 如果是复合类型也是可以的，不过复杂点且这种场景较少，写代码的时候要判断一下要拿到的是复合类型中的哪个属性
    if (isPrimitiveOrPrimitiveWrapper(objClass)) {
     value = obj.toString();
    } else if (objClass.isAssignableFrom(String.class)) {
     value = "\"" + obj.toString() + "\""; 
    }
     
    sql = sql.replaceFirst("\\?", value);
   }
  }
   
  return sql;
 }
  
 /**
  * 处理参数为Map的场景
  */
 private String handleMapParameter(String sql, Map<?, ?> paramMap, List<ParameterMapping> parameterMappingList) {
  for (ParameterMapping parameterMapping : parameterMappingList) {
   Object propertyName = parameterMapping.getProperty();
   Object propertyValue = paramMap.get(propertyName);
   if (propertyValue != null) {
    if (propertyValue.getClass().isAssignableFrom(String.class)) {
     propertyValue = "\"" + propertyValue + "\"";
    }
 
    sql = sql.replaceFirst("\\?", propertyValue.toString());
   }
  }
   
  return sql;
 }
  
 /**
  * 处理通用的场景
  */
 private String handleCommonParameter(String sql, List<ParameterMapping> parameterMappingList, Class<?> parameterObjectClass, 
   Object parameterObject) throws Exception {
  for (ParameterMapping parameterMapping : parameterMappingList) {
   String propertyValue = null;
   // 基本数据类型或者基本数据类型的包装类，直接toString即可获取其真正的参数值，其余直接取paramterMapping中的property属性即可
   if (isPrimitiveOrPrimitiveWrapper(parameterObjectClass)) {
    propertyValue = parameterObject.toString();
   } else {
    String propertyName = parameterMapping.getProperty();
     
    Field field = parameterObjectClass.getDeclaredField(propertyName);
    // 要获取Field中的属性值，这里必须将私有属性的accessible设置为true
    field.setAccessible(true);
    propertyValue = String.valueOf(field.get(parameterObject));
    if (parameterMapping.getJavaType().isAssignableFrom(String.class)) {
     propertyValue = "\"" + propertyValue + "\"";
    }
   }
 
   sql = sql.replaceFirst("\\?", propertyValue);
  }
   
  return sql;
 }
  
 /**
  * 是否基本数据类型或者基本数据类型的包装类
  */
 private boolean isPrimitiveOrPrimitiveWrapper(Class<?> parameterObjectClass) {
  return parameterObjectClass.isPrimitive() || 
    (parameterObjectClass.isAssignableFrom(Byte.class) || parameterObjectClass.isAssignableFrom(Short.class) ||
      parameterObjectClass.isAssignableFrom(Integer.class) || parameterObjectClass.isAssignableFrom(Long.class) ||
      parameterObjectClass.isAssignableFrom(Double.class) || parameterObjectClass.isAssignableFrom(Float.class) ||
      parameterObjectClass.isAssignableFrom(Character.class) || parameterObjectClass.isAssignableFrom(Boolean.class));
 }
  
 /**
  * 是否DefaultSqlSession的内部类StrictMap
  */
 private boolean isStrictMap(Class<?> parameterObjectClass) {
  return parameterObjectClass.isAssignableFrom(StrictMap.class);
 }
  
 /**
  * 是否List的实现类
  */
 private boolean isList(Class<?> clazz) {
  Class<?>[] interfaceClasses = clazz.getInterfaces();
  for (Class<?> interfaceClass : interfaceClasses) {
   if (interfaceClass.isAssignableFrom(List.class)) {
    return true;
   }
  }
   
  return false;
 }
  
 /**
  * 是否Map的实现类
  */
 private boolean isMap(Class<?> parameterObjectClass) {
  Class<?>[] interfaceClasses = parameterObjectClass.getInterfaces();
  for (Class<?> interfaceClass : interfaceClasses) {
   if (interfaceClass.isAssignableFrom(Map.class)) {
    return true;
   }
  }
   
  return false;
 }
  
}

public static Object wrap(Object target, Interceptor interceptor) {
 Map<Class<?>, Set<Method>> signatureMap = getSignatureMap(interceptor);
 Class<?> type = target.getClass();
 Class<?>[] interfaces = getAllInterfaces(type, signatureMap);
 if (interfaces.length > 0) {
  return Proxy.newProxyInstance(
   type.getClassLoader(),
   interfaces,
   new Plugin(target, interceptor, signatureMap));
 }
 return target;
}

<plugins>
  <plugin interceptor="org.xrq.mybatis.plugin.SqlCostInterceptor" />
 </plugins>

SQL：[insert into mail(id, create_time, modify_time, web_id, mail, use_for) values(null, now(), now(), "1", "123@sina.com", "个人使用");]执行耗时[1ms]
SQL：[insert into mail(id, create_time, modify_time, web_id, mail, use_for) values(null, now(), now(), "2", "123@qq.com", "企业使用");]执行耗时[1ms]
SQL：[insert into mail(id, create_time, modify_time, web_id, mail, use_for) values(null, now(), now(), "3", "123@sohu.com", "注册账号使用");]执行耗时[0ms]