Detailed explanation of how to use Pattern to extract required characters in java background

Write before dealing with problems

Due to the iteration of the project function, the ID naming rules in the original page are different from the current naming rules (ps: Since you want to use the original thing, why are compatibility issues not considered during the design, speechless), so all the original IDs need to be extracted.

How to extract the problems encountered?

After searching for many methods, I felt that using Pattern extraction was more in line with the needs. So I started to try.

1.First perform a simple test

String str = "{abc<icon>{def:</icon>}deftfh<icon>a</icon>}";
Pattern p=("<icon>\\{(\\w+)\\:</icon>");
Matcher m=(str2);
        while(()){
            ((1));
            }

OK, no problem, extraction is normal. So some of the strings that need to be extracted are taken out for testing.

2. Project content testing

String str = "\"EquipmentID\":\"SSC_FZ_DQ#MJ23JZ_FZ_CZ_CZGX#YL#SBBM\",";
Pattern p=("\"EquipmentID\":\"(\\w+)\",");
Matcher m=(str2);
        while(()){
            ((1));
            }

The problem is here, nothing is extracted. Then try to extract only the characters in the EquipmentID, and the test is no problem. The problem lies in regular matching. (\\w+) is only suitable for intercepting text parts, and changed to (.*). OK. The SSC_FZ_DQ#MJ23JZ_FZ_CZ_CZGX#YL#SBBM part can be intercepted normally.

3. Do practical

Establish a database connection.

public class CopyOracle2MySQL1 {
    /**
      * Source database, target database connection configuration
       */
    private final String DEST_MYSQL_JDBC_URL = ;
    private final String SOURCE_JDBC_URL = "";
    private final String SOURCE_JDBC_USER = "";
    private final String SOURCE_JDBC_PASSWORD = "";

    public void startImport() throws Exception {
        // Create a connection to two databases        ("");
        //("");

        Connection connDest = (DEST_MYSQL_JDBC_URL);
        //Connection connSource = (SOURCE_JDBC_URL, SOURCE_JDBC_USER, SOURCE_JDBC_PASSWORD);

        try {

            // Manually enter the names of each table (the order needs to be guaranteed to ensure that tables with foreign keys are inserted after the main table)            importTable(connDest, "APP_WGADDATA","qtsc_jk_scjkzttxx");

        } finally {
            // Automatically close database resources            ();
            //();
        }
    }

    private void importTable(Connection connDest, String oracleTableName,String mysqlTableName) throws Exception {

        Statement stmt = null;

        try {

            stmt = ();
            String mysqlSql = "select ZTTNR from qtsc_jk_scjkzttxx qjs where   = '0284fcbdcdbd4da3bdef78ed769515c6'";
            String mysqlSql1 = "select ZTTNR from qtsc_jk_scjkzttxx";
            ResultSet rs = (mysqlSql1);

            Map&lt;String, String&gt; sbbmMap = new HashMap();
            while(()){
                String zttnr = (1);
                //(zttnr);
                Pattern p = ("\"EquipmentID\":\"(.*)\",\"UnitName\"");
                Matcher m=(zttnr);
                while(()){
                    ((1));

                }
                //(sbbmMap);
            }

            // First calculate the SQL statement z of the PreparedStatement of the target database            ResultSetMetaData rsmd = ();

            ();
        }catch (Exception e){

            ();
        }
        finally {
            if(stmt != null) {
                ();
            }
        }
    }

    public static void main(String[] args) throws Exception {
        CopyOracle2MySQL1 ins = new CopyOracle2MySQL1();
        ();
    }

The test results found that the extraction was performed in the early stages of all the rules that matched the rules, and found that the last ", "UnitName" was automatically matched, which was obviously a problem with the rules, so the problem was changed to (.?) to (.?) was solved.

Attachment: JAVA Pattern regular gets the content in curly braces

Use regular expressions to get the desired value in the string:

Get string scene: Hello (hehe)

I need to get "hehe" How to get it?

1. Get it through regular expressions:

        String str = "hello(whee)";
        Pattern p = ("\\(([^\\)]+)");
        Matcher matcher = (str);
        if (() &amp;&amp; () &gt;= 1){
            ((1));
        }

2. Obtain through character interception:

        String str = "hello(whee)";
        String xixi = (("(") + 1, (")"));
        (xixi);

Summarize

This is the article about how to use Pattern to extract required characters in Java backend. For more related Java to extract required characters in Pattern, please search for my previous article or continue browsing the related articles below. I hope everyone will support me in the future!