J2WEB course design example

I found a good article about database query display error: Analysis of mysql coding errors.
And then I have a crack free version navicat . extraction code: dv6k

catalog

• Project Name: xixijiaxiang online e-book City
• Project background: (if I think about it myself, I won't talk about it.)
• Project team members: Cai Xibei, Wang Mushi

Question 1: how to print and output e-book documents
Since it's an online e-book, you need to know how to print it out
Step 1: we need to print a document, such as: test.doc . We need to know the path of this file, so we need to establish a connection with this file

File file = new File(path);  //To establish a connection with a file is to get the path of the file

Step 2: get the input bytes from a file in the file system, that is to say, we change the characters in this file into byte streams

FileInputStream reader = new FileInputStream(file);  //Get input bytes from a file in the file system

Step 3: we read characters into byte stream, but what we get can't be displayed directly, right? So we need to take this byte stream out and store it in byte array byte []

byte[] b = new byte[reader.available()];  //Read byte stream saved to byte array
int len = reader.read(b);        //Bytes read

Step 4: when we get the output byte of this file, we can print it directly

System.out.println(new String(b,0,len));
reader.close();

Complete case:

public class ReadFile {
	public static void main(String[] args) throws Exception {
		//File printout
		readerFile();
	}
	static void readerFile() throws Exception {
		//If we want to output the content of a file, we need to know where the file is first
		File file = new File("C:\\Users\\Administrator\\Desktop\\file\\test.xml");
		//We found the document, but how can we print it out
		FileInputStream reader = new FileInputStream(file);
		byte[] b = new byte[reader.available()];
		int len = reader.read(b);        //Bytes read
		System.out.println(new String(b,0,len));
		reader.close();
	}
}

Running screenshot:

However, when we read documents, we usually need to read them line by line, so here is a case: (web application)

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
   {//read abc.docx Content and output to web page
   	response.setContentType("text/html;charset=utf-8");
   	//Establish a connection
   	File filePath = new File("C:\\Users\\Administrator\\eclipse-workspace\\day0505\\src\\abc.txt");
   	if(!filePath.exists())
   	{//If the file does not exist, tell someone that the resource is missing
   		response.getWriter().println("The resources you need have been lost.....");
   	}else
   	{//File exists
   		InputStream is = new FileInputStream(filePath);
   		InputStreamReader isr = new InputStreamReader(is, "GBK");             //Set the coding mode to prevent garbled code
   		BufferedReader reader = new BufferedReader(isr); 
   		String line = null;
   		while((line=reader.readLine())!=null)
   		{//If the read row is not empty, continue reading 3
   			response.getWriter().println("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"+line+"<br/>");
   		}
   		reader.close();
   		isr.close();
   		is.close();
   	}
   }

Running screenshot:

Question 2: how to find the file that the link clicked on? Premise: database, don't tell me about hyperlink, it's html static, fixed
Step 1: let's assume that there is a folder test, and then there are two folders test1 and test2 in this folder. How do we traverse to print all the files in test1 and test2. So we need to establish a connection with the file test, that is to find the path, right. Let's implement traversal first, and link the database later when the project needs to be used

File file = new File(path:xxx.doc);   //Create a connection to a file
recursionFiles( file);           			//Call the recursive algorithm in step 2

Step 2: use recursive algorithm to traverse the file

//Traverse a specified file directory
	static void recursionFiles(File file) {
		//Get all the files in this directory
		File[] listFiles = file.listFiles();         //List all files in the file
		for(File files:listFiles) {                    //Loop through the listed files
			if(files.isDirectory()) {					//The traversal file is a directory (folder), so you need to recursively traverse the folder again
				System.out.println("\n This is a folder"+files.getName()+":");
				recursionFiles(files);               //Call recursive method again
				System.out.println(files.getName()+"End of file traversal in\n");
			}else {													//Traversal file is not a folder, direct printout
				System.out.println(files.getName());
			}
		}
	}

Complete example:

public class RecursionFile {
	public static void main(String[] args) {
		//Establish a connection
		File file = new File("C:\\Users\\Administrator\\Desktop\\file");
		recursionFiles(file);
	}
	//Traverse a specified file directory
	static void recursionFiles(File file) {
		//Get all the files in this directory
		File[] listFiles = file.listFiles();
		for(File files:listFiles) {
			if(files.isDirectory()) {
				System.out.println("\n This is a folder"+files.getName()+":");
				recursionFiles(files);
				System.out.println(files.getName()+"End of file traversal in\n");
			}else {
				System.out.println(files.getName());
			}
		}
	}
}

Running screenshot:
Path:

Traverse output screenshot:

Now that we've solved the problem, we're making our online bookstore:

emmmmm… Too much, contact me directly for source code! Effect website: Book city
About setting up the server, please contact me to teach you. QQ: 2584163016, please explain the purpose of the verification information