Java reads data source information, and java reads related information.

Java reads data source information, and java reads related information.
I. package com. ofsp. utils; import java. io. IOException; import java. io. inputStream; import java. SQL. connection; import java. SQL. databaseMetaData; import java. SQL. driverManager; import java. SQL. resultSet; import java. SQL. SQLException; import java. util. arrayList; import java. util. list; import java. util. properties; public class performanceutil {public static final String performance_filename = "jdbc. properties "; // public static final String performance_url =" jdbc. url "; // key public static final String performance_username =" jdbc. username "; // key public static final String performance_password =" jdbc. password "; // The key/*** of the password in the data source file reads the configuration file information * @ return Properties configuration file information * @ throws Exception */public static Properties getProperties () throws Exception {InputStream in = null; if (in = null ){//Class. getResourceAsStream () specifies the path of the resource to be loaded to be consistent with the path of the package of the current Class.For example, if you write a MyTest class under the com. test. mycode package, then MyTest. class.getResourceAsStream("name")Find the corresponding resource under the com. test. mycode package. If the name starts with '/', it will start from the root path of classpath. ClassLoader. getResourceAsStream () is located in the root path of classpath no matter whether '/' is included in the resource to be searched. In = Thread. currentThread (). getContextClassLoader (). getResourceAsStream (performance_filename); // The path is the relative path of classpath,ClasspathYesWEB-INFFolderClassesDirectoryIf (in = null) {throw new Exception ("the data source configuration file with the path" + performance_filename + "cannot be found. ") ;}} Properties properties = new Properties (); try {properties. load (in);} catch (IOException e) {e. printStackTrace ();} return properties;}/*** read the configuration file to obtain the database url to connect to the database * @ return String database name * @ throws Exception */public static String getDatabaseURL () throws Exception {Properties p = getProperties (); return p. getProperty (performance_url);}/*** read the configuration file and obtain the username * @ return String username * @ throw S Exception */public static String getUserOfDatabase () throws Exception {Properties p = getProperties (); return p. getProperty (performance_username);}/*** read the configuration file to obtain the password for connecting to the database * @ return String password * @ throws Exception */public static String getPasswordOfDatabase () throws Exception {Properties p = getProperties (); return p. getProperty (performance_password);}/*** get database Connection * @ return * @ throws Exception */public static Connection getConnection () throws Exception {Properties p = getProperties (); String url = p. getProperty (performance_url); String username = p. getProperty (performance_username); String password = p. getProperty (performance_password); return DriverManager. getConnection (url, username, password);}/*** get all table names of the specified database and user * @ param conn connect database object * @ param user * @ param database Database name * @ return */public static List <String> getAllTableNames (Connection conn, String database, String schem, String tableName) {List <String> tableNames = new ArrayList <String> (); if (conn! = Null) {try {DatabaseMetaData metadata = conn. getMetaData (); // Table Name List ResultSet rest = metadata. getTables (database, schem. toUpperCase (), tableName. toUpperCase (), new String [] {"TABLE"}); while (rest. next () {tableNames. add (rest. getString ("TABLE_NAME") ;}} catch (SQLException e) {e. printStackTrace () ;}} return tableNames ;}ii. If the Spring framework is used, you can also get the current data source from the Spring configuration file: the data source file is configured in the spring-context.xml Part: DruidDataSource = ApplicationContextHelper. getBean ("dataSource"); // obtain the data source Connection = dataSource. getConnection (); // obtain the connection String user = dataSource. getUsername (); // obtain the user name. Note: close the connection once it is used up. Otherwise, an overflow error occurs.