java lang classcastexception

Using org. json. JSONException: java. lang. stringcannotbeconvertedtoJSONObject: print the string and check whether the json string is correct. After studying it for a long time, I finally found the problem ,... syn is using org. json. JSONException: java. lang. string cannot be converted to JSONObject: print the Strin

For java. lang. NoClassDefFoundError: org/apache/commons/collections/FastHashMap During Java EE development, when data in the configuration file or user form submitted data is encapsulated in the corresponding attributes of the corresponding JavaBean object: in actual development, use the third method toolkit BeanUtils (the commons-beanutils-xxx.jar depends on t

Package java. Lang. Reflect; Import java. Lang. Ref .*;Import java. util .*; Import sun. Misc. proxygenerator; /*** Example of using proxy*Interface TT {String getst ();} Class STT implements TT {Public String getst (){Return "lqtest ";}} Class myhandler implements invocatio

After the Weblogic8.1 project is transplanted to weblogic9.2, the following error is always reported: Java. Lang. outofmemoryerror: permgen Space>Java. Lang. outofmemoryerror: permgen Space> I checked a lot of information online. The solution is as follows: Solution: Adjust the commenv parameters in BEA, WebLogic, and

Java. lang. IllegalArgumentException: Invalid 'log4jconfiglocation solution, log4jConfigLocation When tomcat is started in MyEclipse, the following error occurs: Java. lang. IllegalArgumentException: Invalid 'log4jconfiglocation' parameter: class path resource [log4j. properties] cannot be resolved to URL because it

When Tomcat is started in MyEclipse, java. lang. OutOfMemoryError: PermGen space, permgenspacetomcat is reported. When Tomcat is started in MyEclipse, java. lang. OutOfMemoryError: PermGen space is reported. This error is reported when the project is too large. The solution is as follows, not all of which work.1. Win

Many people see Java. lang. runtimeexception: Unable to instantiate activity componentinfo {***** activity}: Java. lang. classnotfoundexception: Didn't find class "***** activity"On Path:/data/APP /*******. APK error. In Android development, I also encountered this problem. After two days of struggle, I finally solved

It can be compiled normally, but the error "Java. Lang. noclassdeffounderror: ORG/jaxen/jaxenexception" is reported during running. After some searching, there was no problem, but the jaxen. jar package was not used. Download from http://jaxen.org/ Jaxen is an XPATH engine developed using Java and supports JDOM and dom4j. The error message is as follows

After debugging for almost one day, I am tossing and killing me for a bug. The reason for the bug is that Code When not careful, will: Written: Obviously, A function starts to call itself recursively without limit.In a short time, the stack of the thread where the function is located will be full, so stackoverflowerror will be thrown.Once java. Lang. stackoverflowerror is found, it indicatesProgramThere

Java. Lang. abstractmethoderror: Oracle. JDBC. Driver. oracleconnection. getholdability () IAt com. mchange. v2.c3p0. impl. newpooledconnection. carefulcheckholdability (newpooledconnection. Java: 117)At com. mchange. v2.c3p0. impl. newpooledconnection. At com. mchange. v2.c3p0. wrapperconnectionpooldatasource. getpooledconnection (wrapperconnectionpooldatasource

Exception in thread "main" java. lang. NoSuchMethodError: org. objectweb. asm. ClassWriter. When learning CGlib dynamic proxy, the following error occurs: Exception in thread "main" java. lang. NoSuchMethodError: org. objectweb. asm. ClassWriter. After finding the answer on Baidu, it is caused by jar package confl

Parameter package There is no getter for property named 'xxx' in 'class java. lang. string' in mybatisgetter I. Problems Found Select num, name, phone from studentAND num = # {num}When you pass in a String to the Mybatis query, There is no getter for property named 'num' in 'class java. lang. string' is reported '. Ii

Byte [] B = {1, 2, 20,108 }; String stmp = java. Lang. Integer. tohexstring (B [N] 0xff) In 32-bit computers, numbers are stored in 32 format. If a byte (8-bit) number is used, its 24-bit height is a random number, which is 8-bit lower. Is the actual data. The parameter of Java. Lang. Integer. tohexstring () meth

Check whether there is any exception: Java. Lang. classnotfoundexception: org. springframework. Web. Context. contextloaderservlet Therefore, contextloaderservlet is not loaded successfully, leading to failure in building spring containers in Web. xml! Therefore, when you reference webapplicationcontextutils, java. Lang