org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object

1 问题描述 

mybatis3.2.x版本，做压力测试，并发200用户，出现了如下异常.

org.apache.ibatis.builder.BuilderException: Error evaluating expression 'size() > 0'. Cause: org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object [one, two] [java.lang.IllegalAccessException: Class org.apache.ibatis.ognl.OgnlRuntime can not access a member of class java.util.Collections$UnmodifiableCollection with modifiers "public"]
at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:47)
at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:29)
at OgnlConcurrentTest$1.run(OgnlConcurrentTest.java:51)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object [one, two] [java.lang.IllegalAccessException: Class org.apache.ibatis.ognl.OgnlRuntime can not access a member of class java.util.Collections$UnmodifiableCollection with modifiers "public"]
at org.apache.ibatis.ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:837)
at org.apache.ibatis.ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:61)
at org.apache.ibatis.ognl.OgnlRuntime.callMethod(OgnlRuntime.java:860)
at org.apache.ibatis.ognl.ASTMethod.getValueBody(ASTMethod.java:73)
at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170) 2 解决方案 

在网上搜了一桶，找到原因是mybatis3.2.x版本引用ognl的版本为2.6.9，出问题的地方代码如下。

Modifier.isPublic

存在问题，好在ognl2.7版本已经修复,故将mybatis版本升级到mybatis3.3.x以上，同时升级mybatis-spring到1.3.x以上即可。 

因为mybatis-spring1.2.x引用的mybatis版本还是mybatis3.2.x，故需要升级。 



public static Object invokeMethod(Object target, Method method, Object[] argsArray)
throws InvocationTargetException, IllegalAccessException
{
boolean wasAccessible = true;

if (securityManager != null) {
try {
securityManager.checkPermission(getPermission(method));
} catch (SecurityException ex) {
throw new IllegalAccessException("Method [" + method + "] cannot be accessed.");
}
}
if (((!Modifier.isPublic(method.getModifiers())) || (!Modifier.isPublic(method.getDeclaringClass().getModifiers()))) &&
(!(wasAccessible = method.isAccessible()))) {
method.setAccessible(true);
}

Object result = method.invoke(target, argsArray);
if (!wasAccessible) {
method.setAccessible(false);
}
return result;
}参考资料 

MyBatis 3.2.x版本在并发情况下可能出现的bug及解决办法