根据数据库表结构生成java类

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import android.ConnectionFactory;

/**
* 根据数据库表 生成java 实体类
*
* @author DLHT
* @time 2015年9月29日下午4:13:42
* @className GenEntityTool.java
*/
public class GenEntityTool {
private String tablename = "test";

private String[] colnames; // 列名数组

private String[] colTypes; // 列名类型数组

private int[] colSizes; // 列名大小数组

private boolean f_util = false; // 是否需要导入包java.util.*

private boolean f_sql = false; // 是否需要导入包java.sql.*

public GenEntityTool() {

getTablesName();

Connection conn = null;
PreparedStatement pstmt = null;
ResultSetMetaData rsmd = null;

conn = ConnectionFactory.getInstance().getConnection();
String strsql = "select * from " + tablename;
try {
pstmt = conn.prepareStatement(strsql);
rsmd = pstmt.getMetaData();
int size = rsmd.getColumnCount(); // 共有多少列
colnames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
for (int i = 0; i < rsmd.getColumnCount(); i++) {
colnames[i] = rsmd.getColumnName(i + 1);
colTypes[i] = rsmd.getColumnTypeName(i + 1);
if (colTypes[i].equalsIgnoreCase("datetime")) {
f_util = true;
}
if (colTypes[i].equalsIgnoreCase("image")
|| colTypes[i].equalsIgnoreCase("text")) {
f_sql = true;
}
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}
String content = parse(colnames, colTypes, colSizes);

try {
FileWriter fw = new FileWriter(initcap(tablename) + ".java");

PrintWriter pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
pw.close();
} catch (IOException e) {
e.printStackTrace();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
ConnectionFactory.getInstance().closeConnection(conn, pstmt, null);
rsmd = null;
}
}

/**
*    获取当前数据中的表名称
* @methodName getTablesName
* @time 2015年9月29日下午4:52:26
* @packageName fanshe
*/
public List<String> getTablesName(){
List<String> list = null;
Connection conn = null;
DatabaseMetaData md = null;
ResultSet rs = null;
conn = ConnectionFactory.getInstance().getConnection();
try {
md = conn.getMetaData();
rs = md.getTables(null, null, null, null);
if(rs!=null&&rs.next()){
list = new ArrayList<String>();
}
while (rs.next()) {
//System.out.println("|表"+(i++)+":"+rs.getString("TABLE_NAME"));
String tableName = rs.getString("TABLE_NAME");
list.add(tableName);
}

} catch (SQLException e) {
e.printStackTrace();
} finally {
ConnectionFactory.getInstance().closeConnection(conn, null, rs);
md = null;
}
return list;
}

/**
* 解析处理(生成实体类主体代码)
*/
private String parse(String[] colNames, String[] colTypes, int[] colSizes) {
StringBuffer sb = new StringBuffer();
if (f_util) {
sb.append("import java.util.Date;\r\n");
}
if (f_sql) {
sb.append("import java.sql.*;\r\n\r\n\r\n");
}
sb.append("public class " + initcap(tablename) + " {\r\n");
processAllAttrs(sb);
processAllMethod(sb);
sb.append("}\r\n");

//markerBean(initcap(tablename), sb.toString());

return sb.toString();

}

/**
*  创建java 文件  将生成的属性 get/set 方法 保存到 文件中
* markerBean
* @time 2015年9月29日下午4:15:22
* @packageName fanshe
* @param className  类名称
* @param content    类内容  包括属性 getset 方法
*/
public void markerBean(String className, String content) {
String folder = System.getProperty("user.dir") + "/src/fanshe/";

File file = new File(folder);
if (!file.exists()) {
file.mkdirs();
}
String fileName = folder + className + ".java";

try {
File newdao = new File(fileName);
FileWriter fw = new FileWriter(newdao);
fw.write(content);
fw.flush();
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* 生成所有的方法
*
* @param sb
*/
private void processAllMethod(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tpublic void set" + initcap(colnames[i]) + "("
+ sqlType2JavaType(colTypes[i]) + " " + colnames[i]
+ "){\r\n");
sb.append("\t\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");
sb.append("\t}\r\n");

sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get"
+ initcap(colnames[i]) + "(){\r\n");
sb.append("\t\treturn " + colnames[i] + ";\r\n");
sb.append("\t}\r\n");
}
}

/**
* 解析输出属性
*
* @return
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " "
+ colnames[i] + ";\r\n");

}
}

/**
* 把输入字符串的首字母改成大写
*
* @param str
* @return
*/
private String initcap(String str) {
char[] ch = str.toCharArray();
if (ch[0] >= 'a' && ch[0] <= 'z') {
ch[0] = (char) (ch[0] - 32);
}
return new String(ch);
}

private String sqlType2JavaType(String sqlType) {
if (sqlType.equalsIgnoreCase("bit")) {
return "bool";
} else if (sqlType.equalsIgnoreCase("tinyint")) {
return "byte";
} else if (sqlType.equalsIgnoreCase("smallint")) {
return "short";
} else if (sqlType.equalsIgnoreCase("int")) {
return "int";
} else if (sqlType.equalsIgnoreCase("bigint")) {
return "long";
} else if (sqlType.equalsIgnoreCase("float")) {
return "float";
} else if (sqlType.equalsIgnoreCase("decimal")
|| sqlType.equalsIgnoreCase("numeric")
|| sqlType.equalsIgnoreCase("real")) {
return "double";
} else if (sqlType.equalsIgnoreCase("money")
|| sqlType.equalsIgnoreCase("smallmoney")) {
return "double";
} else if (sqlType.equalsIgnoreCase("varchar")
|| sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar")
|| sqlType.equalsIgnoreCase("nchar")) {
return "String";
} else if (sqlType.equalsIgnoreCase("datetime")) {
return "Date";
}

else if (sqlType.equalsIgnoreCase("image")) {
return "Blob";
} else if (sqlType.equalsIgnoreCase("text")) {
return "Clob";
}
return null;
}

public static void main(String[] args) {
new GenEntityTool();
}
}

/**
*    获取当前数据中的表名称
* @methodName getTablesName
* @time 2015年9月29日下午4:52:26
* @packageName fanshe
*/
public List<String> getTablesName(){
List<String> list = null;
Connection conn = null;
DatabaseMetaData md = null;
ResultSet rs = null;
conn = ConnectionFactory.getInstance().getConnection();
try {
md = conn.getMetaData();
rs = md.getTables(null, null, null, null);
if(rs!=null&&rs.next()){
list = new ArrayList<String>();
}
while (rs.next()) {
//System.out.println("|表"+(i++)+":"+rs.getString("TABLE_NAME"));
String tableName = rs.getString("TABLE_NAME");
list.add(tableName);
}

} catch (SQLException e) {
e.printStackTrace();
} finally {
ConnectionFactory.getInstance().closeConnection(conn, null, rs);
md = null;
}
return list;
}