Mycelipse Error Report adjustment method, mycelipse Error Report

Mycelipse Error Report adjustment method, mycelipse Error Report

1. When the myclipse project appears, a red exclamation point appears.

-- 1) cause: due to the lack of jar packages due to the import and export of different versions of myclipse, it is best to create a new project and copy the prepared files to solve the problem.

-- 2) solution: (1) the Server tomcat is not loaded. reconfigure the Server tomcat.

(2) The JAr package is missing. Project-Buildpath-configure buid path-libraies-select the wrong JAR package to delete and reload the new jar package.

(3) The best way is to re-create a project file and copy the file.

2. When an error occurs in web. xml, You have to restart the server and cannot refresh the server.

-- 2) solution: the web. xml file is missing. First, create a project, copy the existing web. xml project file, and then paste it. The problem is solved.

1. When myclipse has two errors

(1) Running exception: Features

No exception/error detected on the page, the program runs properly, but no result

Processing Method: From the past (from. jsp to biz-dao), the test statement is placed in the return value of the variable/parameter/method/to check whether there is a value. Add the print statement in src, system. out. ptint ([parameter] [SQL statement] [variable]). If a print statement appears, it indicates that there is no error. If it does not, it indicates an error. modify this field.

(2) Compilation exception: Features

Page detected exceptions/errors,

Solution: Look at the exception point interface, starting from the first exception point, and then find the code of the first exception point page and the code associated with the subsequent page, and push it from the back

3. when copying a new web project file, do not directly paste it (1). This may easily cause the web project to become a Java file. When a J indicates a Java file appears in the tag above the project, in this case, the web solution cannot be accessed, and the web is easily caused by pasting files one by one (2. xml missing, when the web. when xml is missing, the servlet class cannot be accessed because the browser first accesses the web. xml and then access servlet Class 4. differentiation = and equals () (1) = is to judge whether the memory address is the same period null represents a variable is null or a reference does not exist (an empty reference is returned to the variable, represents the existence of a variable, but there is nothing in the variable), (applicable to the reference type data, because String is a class) int a; a = null (the variable itself exists in the memory, but there is nothing.) (2) equals () is used to determine whether the string is the same or not. An error occurs: When a variable uses both = and equals (), always put = in front, if equals () is placed behind the variable, otherwise the Null Pointer Error cause is reported: = indicates that the variable exists in the memory, you can call this method equals () before =, the variable may not exist.