import java.io.File;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import org.apache.commons.io.FileUtils;

public class GenEntityUtil {
	
    private String[] colnames; // 列名陣列
    private String[] colTypes; // 列名型別陣列
    private int[] colSizes; // 列名大小陣列
    private boolean f_util = false; // 是否需要匯入包java.util.*
    private boolean f_sql = false; // 是否需要匯入包java.sql.*

    public GenEntityUtil(String packagePath, String tableName) {
        Connection conn = DatabaseUtils.openConnection(); // 得到資料庫連線
        PreparedStatement pstmt = null;
        String strsql = "select * from " + tableName;
        try {
            pstmt = conn.prepareStatement(strsql);
            ResultSetMetaData 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] = this.getCamelStr(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);
            }
            try {
            	String content = parse(colnames, colTypes, colSizes, packagePath, tableName);
            	String path = System.getProperty("user.dir") + "/src/" + packagePath.replaceAll("\\.", "/");
                File file = new File(path);
                if(!file.exists()){
                	file.mkdirs();
                }
                String resPath = path+"/"+initcap(tableName) + ".java";
                System.out.println("resPath=" + resPath);
                FileUtils.writeStringToFile(new File(resPath), content);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
        	DatabaseUtils.closeDatabase(conn, pstmt, null);
        }
    }

    /**
    * 解析處理(生成實體類主體程式碼)
    */
    private String parse(String[] colNames, String[] colTypes, int[] colSizes, String packagePath, String tableName) {
        StringBuffer sb = new StringBuffer();
        sb.append("package " + packagePath + ";\r\n\r\n");
        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\r\n");
        processAllAttrs(sb);
        sb.append("\r\n");
        processAllMethod(sb);
        sb.append("}\r\n");
        System.out.println(sb.toString());
        return sb.toString();

    }

    /**
    * 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\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\r\n");
        }
    }

    /**
    * 解析輸出屬性
    * 
    * @return
    */
    private void processAllAttrs(StringBuffer sb) {
        for (int i = 0; i < colnames.length; i++) {
            sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
        }
    }

    /**
    * 把輸入字串的首字母改成大寫
    * 
    * @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 this.getCamelStr(new String(ch));
    }
    
    //例：user_name --> userName
    private String getCamelStr(String s){
    	while(s.indexOf("_")>0){
			int index = s.indexOf("_");
			//System.out.println(s.substring(index+1, index+2).toUpperCase());
			s = s.substring(0, index) + s.substring(index+1, index+2).toUpperCase() + s.substring(index+2);
		}
		return s;
    }

    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") || sqlType.equalsIgnoreCase("integer")) {
            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) {
    	String packagePath = "com.test.model";
    	String tableName = "test";
        new GenEntityUtil(packagePath,tableName);
    }
    
}