JAVA开发错误总结(仅记录遇到的错误---后续不断更新......)

=======华丽分割线(工具总结)=====================

1:Maven项目中junit测试找不到主类的问题

Class not found com.test.utils.test
java.lang.ClassNotFoundException: com.test.utils.test
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClass(RemoteTestRunner.java:688)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClasses(RemoteTestRunner.java:421)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:444)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

解决方法:找到图一修改成为图二

图1：



图2:



========华丽分割线(数据库总结)==================

Mongo查询正确格式:

Query query = new Query();
String startTime = "2014-03-29 16:58";
String endTime = "2014-04-09 14:16";
query.addCriteria(Criteria.where("time").gte(startTime).lte(endTime));

json格式:



查询时间错误案例:

报错:org.springframework.data.mongodb.InvalidMongoDbApiUsageException: Due to limitations of the com.mongodb.BasicDBObject, you can't add a second 'time' expression specified as 'time

Query query = new Query();
String startTime = "2014-03-29 16:58";
String endTime = "2014-04-09 14:16";
query.addCriteria(Criteria.where("time").is(startTime).and("time").is(endTime));

分析:根据前面的json格式可以看出time其实已经存在了,导致二次创建time(看下面事例)

Query query = new Query();
String startTime = "2014-03-29 16:58";
query.addCriteria(Criteria.where("time").is(startTime).and("sex").is("男"));

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