Get the table structure primary key in the database by JDBC the type of the field and the application to generate the entity class

Http://www.cnblogs.com/lbangel/p/3487796.html

Package cn.test;

Import Java.io.File;
Import Java.io.FileOutputStream;
Import java.sql.Connection;
Import Java.sql.DatabaseMetaData;
Import Java.sql.DriverManager;
Import Java.sql.ResultSet;
Import Java.text.SimpleDateFormat;
Import Java.util.Date;
Import Java.util.HashMap;
Import Java.util.Map;

public class Testall {
private static String Path = "D:\\tool\\project\\dynamictable\\src\\cn\\test\\entity";
private static String Pkname = "Com.mysql.jdbc.Driver";
private static String URL = "Jdbc:mysql://192.168.1.220:3306/person";
private static string[] Classnames = new string[] {"Shipstopping",
"Arriveship", "Tblusertype"};
private static map<string, string> fktablenamesandpk = new hashmap<string, string> ();

public static void Main (string[] args) {
Test ();
}

public static void Test () {
Connection conn = null;
DatabaseMetaData metaData = null;
ResultSet rs = null;
ResultSet CRS = NULL;
try {
Class.forName ("Com.microsoft.sqlserver.jdbc.SQLServerDriver");
conn = drivermanager.getconnection (URL, "admin", "123");
String Catalog = Conn.getcatalog (); Catalog is actually the database name
MetaData = Conn.getmetadata ();
File Dirfile = new file (path);
if (!dirfile.exists ()) {
Dirfile.mkdirs ();
}
Get table
rs = Metadata.gettables (null, "%", "%", new string[] {"TABLE"});
while (Rs.next ()) {
String tablename = rs.getstring ("table_name");
String classname = getclassnamebytablename (tablename);
StringBuffer sb = new StringBuffer ();
StringBuffer sbpackage = new StringBuffer ();
Sbpackage.append ("Package cn.test.entity;\r\n\r\n");
Sbpackage.append ("Import javax.persistence.column;\r\n");
Sbpackage.append ("Import javax.persistence.entity;\r\n");
Sbpackage.append ("Import javax.persistence.generatedvalue;\r\n");
Sbpackage.append ("Import javax.persistence.id;\r\n");
Sbpackage.append ("Import javax.persistence.table;\r\n\r\n");
Sb.append ("\r\[email protected]\r\n");
Sb.append ("@Table (name = \" "+ tablename +" \ ") \ r \ n");
Sb.append ("public class" + ClassName
+ "Implements java.io.Serializable {\ r \ n");
Gets the columns of the current table
CRS = Metadata.getcolumns (null, "%", TableName, "%");
Gets the referenced table whose primary key is the foreign key of the current table
Fktablenamesandpk.clear ();
ResultSet foreignkeyresultset = metadata.getimportedkeys (catalog, NULL, tablename);
while (Foreignkeyresultset.next ()) {
String pktablenname = foreignkeyresultset.getstring ("Pktable_name"); FOREIGN key table
String fkcolumnname = foreignkeyresultset.getstring ("Fkcolumn_name"); FOREIGN key
if (!fktablenamesandpk.containskey (fkcolumnname))
Fktablenamesandpk.put (Fkcolumnname, pktablenname);
}
Foreignkeyresultset.close ();
while (Crs.next ()) {
String ColumnName = crs.getstring ("column_name");
String ColumnType = crs.getstring ("type_name");
System.out.println ("--------------------------" + ColumnType);
if (Existfkcolumn (ColumnName)) {
String fkclassname = Getclassnamebytablename (Fktablenamesandpk.get (columnname));
Sbpackage.append ("import" + Pkname + "." + fkclassname+ "; \ r \ n");
Sb.append ("\t/** */\r\n");
Sb.append ("\tprivate" + fkclassname + "+ columnname+"; \ r \ n ");
} else {
Sb.append ("\t/** */\r\n");
Sb.append ("\tprivate" + getfieldtype (ColumnType, sbpackage) + "" + ColumnName + "; \ r \ n");
}
}
Sb.append ("}");
File File = new file (dirfile, classname + ". Java");
if (file.exists ()) {
File.delete ();
}
GetTitle (Sbpackage, classname);
FileOutputStream outputstream = new FileOutputStream (file);
Outputstream.write (Sbpackage.tostring (). GetBytes ());
Outputstream.write (Sb.tostring (). GetBytes ());
Outputstream.close ();
System.out.println (classname + "create success ... ");
}
} catch (Exception e) {
E.printstacktrace (System.out);
} finally {
try {
if (null! = RS) {
Rs.close ();
}
if (null! = conn) {
Conn.close ();
}
} catch (Exception E2) {
}
}
}

/**
* Get the class name based on the table name
*
* @param tablename
* @return
*/
private static string Getclassnamebytablename (String tablename) {
String classname = getclassname (tablename);
for (String name:classnames) {
if (Name.tolowercase (). Equals (Tablename.tolowercase ())) {
classname = name;
}
}
return classname;
}

private static Boolean Existfkcolumn (String columnname) {
if (FKTABLENAMESANDPK! = null) {
if (Fktablenamesandpk.containskey (ColumnName))
return true;
}
return false;
}

/**
* Suitable for the table name is a single word, for example: The table name is Tbluser class name is Tbluser; When the table name is the user class name is user; When the surface is usertype (two words)
* When the class name is usertype, if you want to usertype, add the desired class name to the Classnames field (which is not case sensitive to the database table name).
*
* @param tablename
* @return
*/
public static string GetClassName (String tablename) {
String res = tablename.tolowercase ();
if (Tablename.startswith ("TBL")) {
Return tablename.substring (0, 4) + res.substring (4);
}
Return tablename.substring (0, 1). toUpperCase () + res.substring (1);
}

/**
* Set field type MySQL data type
*
* @param columntype
* Column type String
* @param sbpackage
* Package Package Information
* @return
*/
public static string GetFieldType (String columntype, StringBuffer sbpackage) {
/*
* Tinyblob Tinyblob byte[]
Tinytext varchar java.lang.string
Blob blob byte[]
Text varchar java.lang.string
Mediumblob Mediumblob byte[]
Mediumtext varchar java.lang.string
Longblob Longblob byte[]
Longtext varchar java.lang.string
Enum (' value1 ', ' value2 ',...) char java.lang.string
Set (' value1 ', ' value2 ',...) char java.lang.string
*/
ColumnType = Columntype.tolowercase ();
if (columntype.equals ("varchar") | | | columntype.equals ("nvarchar")
|| Columntype.equals ("char")
// || Columntype.equals ("Tinytext")
// || Columntype.equals ("text")
// || Columntype.equals ("Mediumtext")
// || Columntype.equals ("Longtext")
) {
return "String";
} else if (Columntype.equals ("Tinyblob")
|| Columntype.equals ("blob")
|| Columntype.equals ("Mediumblob")
|| Columntype.equals ("Longblob")) {
return "byte[]1111";
} else if (Columntype.equals ("datetime")
|| Columntype.equals ("date")
|| Columntype.equals ("timestamp")
|| Columntype.equals ("Time")
|| Columntype.equals ("Year")) {
Sbpackage.append ("Import java.util.date;\r\n");
return "Date";
} else if (Columntype.equals ("bit")
|| Columntype.equals ("int")
|| Columntype.equals ("tinyint")
|| Columntype.equals ("smallint")
// || Columntype.equals ("bool")
// || Columntype.equals ("Mediumint")
// || Columntype.equals ("bigint")
) {
return "int";
} else if (Columntype.equals ("float")) {
return "Float";
} else if (Columntype.equals ("double")) {
return "Double";
} else if (Columntype.equals ("decimal")) {
Sbpackage.append ("Import java.math.bigdecimal;\r\n");
return "BigDecimal";
}
return "ErrorType";
}

/**
* Set Class caption Comment
*
* @param sbpackage
* @param className
*/
public static void GetTitle (StringBuffer sbpackage, String className) {
SimpleDateFormat format = new SimpleDateFormat ("yyyy mm month DD day");
Sbpackage.append ("\r\n/**\r\n");
Sbpackage.append ("*\r\n");
Sbpackage.append ("* Title:" + className + "<br/>\r\n");
Sbpackage.append ("* Description: <br/>\r\n");
Sbpackage.append ("*\r\n");
Sbpackage.append ("* Make information: DATE:" + format.format (new Date ())
+ "name:author\r\n");
Sbpackage.append ("*\r\n");
Sbpackage.append ("* Modify information <br/>\r\n");
Sbpackage.append ("* Modification date Modified by modification of the modified content <br/>\r\n");
Sbpackage.append ("*\r\n");
Sbpackage.append ("*/\r\n");
}

}

Get the table structure primary key in the database by JDBC the type of the field and the application to generate the entity class