Various java implementation programs for reading and writing text files

First look at the simplest java reading text files by line? The code is as follows:

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FileReader reader = new FileReader ("D: \ www.111cn.net \ feisanWeb \ src \ 265_url.txt "); BufferedReader br = new BufferedReader (reader ); String s1 = null; While (s1 = br. readLine ())! = Null ){   } Br. close (); Reader. close ();

The following operations are performed in combination with the database:

However, you cannot import data at the time of import. After viewing the data, you will find that all data formats do not contain the table name.

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Insert into (id, stat_date, referrer, func, catid, user_type, action_stat, channel) VALUES (240092, "2012-3-6", www.111cn.net,-10,116 11,-10, 65: 4.0; 57: 1.0; 52: 1.0 ","-10 "); Insert into (id, stat_date, referrer, func, catid, user_type, action_stat, channel) VALUES (240093, "2012-3-6", "baidu.com",-1, 10587,-10, "65: 273.0", "-10 ");

A total of more than 60 thousand entries. If it takes a long time to add a table name one by one, we can use SQL to batch insert the value of VALUES;

According to the form of SQL script, we only need to replace the ";" following the brackets of VALUES with a comma. The final form is

The code is as follows:

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(240092, "2012-3-6", "renren.com",-10,116 11,-10, "65: 4.0; 57: 1.0; 52: 1.0", "-10 "), (240093, "2012-3-6", "baidu.com",-1, 10587,-10, "65: 273.0", "-10 "), (240094, "2012-3-6", "baidu.com",-1, 10589,-10, "65: 1040.0; 57: 6.0; 52: 10.0", "-10 "), (240095, "2012-3-6", "qq.com",-10,119 13,-10, "65: 1.0", "channelId_846 "), (240096, "2012-3-6", "baidu.com",-1, 10581,-10, "65: 1423.0; 57: 5.0; 52: 5.0", "-10 "), (240097, "2012-3-6", "baidu.com",-1, 10583,-10, "57: 20.0; 52: 23.0; 65: 2823.0", "-10 "),

In this way, we only need to add

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Insert into t_xxx (id, stat_date, referrer, func, catid, user_type, action_stat, channel) VALUES

You can insert databases in batches. Below is the JavaIO processing program;

   

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Public static void main (String [] args) throws Exception { BufferedReader in = new BufferedReader (new FileReader ("D: \ SQL. SQL"); // The text file to be read BufferedWriter br = new BufferedWriter (new FileWriter ("D: \ aaa. SQL"); // output result file String s = ""; Pattern pattern = Pattern. compile (". * [)] [;]"); // regular expression matches the end of an SQL statement. Matcher m = null; Int I = 1; While (s = in. readLine ())! = Null ){ M = pattern. matcher (s ); If (m. matches ()){ System. out. println (I ++ ); S = s. replace (");", "),"); // replace              } If (! S. matches ("*") {// removes blank lines Br. write (s ); Br. write ("n ");              }          } // Close In. close (); Br. flush (); Br. close ();     }

Fast execution speed, less than 2 seconds;

/*
* Simple example of reading/writing text files
* There are three examples:
* 1.
* 2.
* 3. Read the content of one file and write it to another file.
* It also shows that if the content read from the input stream is written to the output stream (text stream only)
* The three examples can exist independently, so you can only view one of them as needed.
*/

The code is as follows:

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Import java. io. BufferedReader; Import java. io. FileInputStream; Import java. io. FileOutputStream; Import java. io. IOException; Import java. io. InputStream; Import java. io. InputStreamReader; Import java. io. OutputStream; Import java. io. OutputStreamWriter; Import java. io. PrintStream; Import java. io. PrintWriter; Example of reading a file into memory (StringBuffer) Public final class AccessTextFile { /** * 1. Read the text in the stream into a StringBuffer. * @ Throws IOException */ Public void readToBuffer (StringBuffer buffer, InputStream is) Throws IOException { String line; // used to save the content read by each row BufferedReader reader = new BufferedReader (new InputStreamReader (is )); Line = reader. readLine (); // read the first row While (line! = Null) {// if line is null, the read is complete. Buffer. append (line); // add the read content to the buffer. Buffer. append ("n"); // add a line break Line = reader. readLine (); // read the next row         }     } /** * 2. Demonstrate reading the content in StringBuffer into the stream */ Public void writeFromBuffer (StringBuffer buffer, OutputStream OS ){ // Use PrintStream to conveniently output content to the output stream // Its object usage is the same as that of System. out. // (System. out itself is a PrintStream object) PrintStream ps = new PrintStream (OS ); Ps. print (buffer. toString ());     } /** * 3 *. Copy the content from the input stream to the input stream. * @ Throws IOException */ Public void copyStream (InputStream is, OutputStream OS) throws IOException { // For the read process, see the comments in readToBuffer. String line; BufferedReader reader = new BufferedReader (new InputStreamReader (is )); PrintWriter writer = new PrintWriter (new OutputStreamWriter (OS )); Line = reader. readLine (); While (line! = Null ){ Writer. println (line ); Line = reader. readLine ();         } Writer. flush ();                                 }

This is the case for text file operations. If you have any questions, refer to the following section.