C #. NET Verification Code Intelligent Recognition learning notes --- 06 solve the java jre problem: when JTessBoxEditor. jar is opened, it cannot be found or the Main class com. sun. tools. javac. Main cannot be loaded,

C #. NET Verification Code Intelligent Recognition learning notes --- 06 solve the java jre problem: when JTessBoxEditor. jar is opened, it cannot be found or the Main class com. sun. tools. javac. Main cannot be loaded,

Technology qq exchange group: JavaDream: 251572072
Download the tutorial and communicate online: it.yunsit.cn

I found this problem online,

Problem description: My problem is that the following error occurs when I use javac to compile the test project:

Error: The Main class com. sun. tools. javac. Main cannot be loaded.

Solution: When this error occurs, Baidu, many people say that the environment variable settings are incorrect, but check the environment variables.

At this time, the error message contains javac. I guess the javac file cannot be found, so I went to the jdk \ bindirectory and found that there was no javac.exe file.

Hosts file. I used jdk

Install it in D: \ JAVA and jre under D: \ JAVA. Then uninstall and reinstall it. Install jdk in D: \ JAVA \ JDK, and install jre in D: \ JAVA \ JRE and javac Compilation

Test Program. No error. Installation successful.

---------------------------------------------------------------

It seems that javac.exe is not very small, but it can be used after this operation ..

----------------------------------------------------------------

C Language & |! What are

& Is the address fetch operator used to extract the address of a variable.
For example, if you define a variable, the system will allocate a space in the memory during compilation.
The location of the space in the memory is its address. & Extract its address.
E. g int a; assign an address to it during compilation, for example, 2000; & a is 2000.
If an integer pointer Variable p, p = & a; is defined, the address 2000 of a is assigned to p. P = 2000 after running.
Another example is scanf ("% d", & a). When you enter 3, it first knows the address of a according to & a, and finds the space of a in the memory by the address, write 3 to this space.
* Is a pointer operator, which is opposite to &. It extracts the value of a Variable Based on the address of the variable.
For example, * the value of a is 3 of variable.
The following is a summary of the pointer used in the definition and description.
Int * p; defines a pointer to integer data.
Int * p [n]; defines the pointer array p, which consists of n pointer elements pointing to integer data.
Int (* p) [n]; p is the pointer variable pointing to a one-dimensional array containing n elements.
Int * p (); p is the function that returns a pointer pointing to integer data.
Int (* p) (); p is the pointer to the function. This function returns an integer value.
Int ** p; p is a pointer variable that points to an integer Data Pointer variable.
If you want to learn more about the system, you can refer to tan haoqiang's c Programming (the third edition), which is easy to understand. Is a good C language learning material.

C Language & |! What are

& Is the address fetch operator used to extract the address of a variable.
For example, if you define a variable, the system will allocate a space in the memory during compilation.
The location of the space in the memory is its address. & Extract its address.
E. g int a; assign an address to it during compilation, for example, 2000; & a is 2000.
If an integer pointer Variable p, p = & a; is defined, the address 2000 of a is assigned to p. P = 2000 after running.
Another example is scanf ("% d", & a). When you enter 3, it first knows the address of a according to & a, and finds the space of a in the memory by the address, write 3 to this space.
* Is a pointer operator, which is opposite to &. It extracts the value of a Variable Based on the address of the variable.
For example, * the value of a is 3 of variable.
The following is a summary of the pointer used in the definition and description.
Int * p; defines a pointer to integer data.
Int * p [n]; defines the pointer array p, which consists of n pointer elements pointing to integer data.
Int (* p) [n]; p is the pointer variable pointing to a one-dimensional array containing n elements.
Int * p (); p is the function that returns a pointer pointing to integer data.
Int (* p) (); p is the pointer to the function. This function returns an integer value.
Int ** p; p is a pointer variable that points to an integer Data Pointer variable.
If you want to learn more about the system, you can refer to tan haoqiang's c Programming (the third edition), which is easy to understand. Is a good C language learning material.