根据数据库表结构生成java类-白红宇

根据数据库表结构生成java类

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发布时间：2019-06-12

本文共 9757 字，大约阅读时间需要 32 分钟。

1 import java.io.File;  2 import java.io.FileWriter;  3 import java.io.IOException;  4 import java.io.PrintWriter;  5 import java.sql.Connection;  6 import java.sql.DatabaseMetaData;  7 import java.sql.PreparedStatement;  8 import java.sql.ResultSet;  9 import java.sql.ResultSetMetaData; 10 import java.sql.SQLException; 11 import java.util.ArrayList; 12 import java.util.List; 13   14 import android.ConnectionFactory; 15   16 /** 17  * 根据数据库表 生成java 实体类 18  * 19  * @author DLHT 20  * @time 2015年9月29日下午4:13:42 21  * @className GenEntityTool.java 22  */ 23 public class GenEntityTool { 24     private String tablename = "test"; 25   26     private String[] colnames; // 列名数组 27   28     private String[] colTypes; // 列名类型数组 29   30     private int[] colSizes; // 列名大小数组 31   32     private boolean f_util = false; // 是否需要导入包java.util.* 33   34     private boolean f_sql = false; // 是否需要导入包java.sql.* 35   36     public GenEntityTool() { 37   38         getTablesName(); 39   40   41         Connection conn = null; 42         PreparedStatement pstmt = null; 43         ResultSetMetaData rsmd = null; 44   45         conn = ConnectionFactory.getInstance().getConnection(); 46         String strsql = "select * from " + tablename; 47         try { 48             pstmt = conn.prepareStatement(strsql); 49             rsmd = pstmt.getMetaData(); 50             int size = rsmd.getColumnCount(); // 共有多少列 51             colnames = new String[size]; 52             colTypes = new String[size]; 53             colSizes = new int[size]; 54             for (int i = 0; i < rsmd.getColumnCount(); i++) { 55                 colnames[i] = rsmd.getColumnName(i + 1); 56                 colTypes[i] = rsmd.getColumnTypeName(i + 1); 57                 if (colTypes[i].equalsIgnoreCase("datetime")) { 58                     f_util = true; 59                 } 60                 if (colTypes[i].equalsIgnoreCase("image") 61                         || colTypes[i].equalsIgnoreCase("text")) { 62                     f_sql = true; 63                 } 64                 colSizes[i] = rsmd.getColumnDisplaySize(i + 1); 65             } 66             String content = parse(colnames, colTypes, colSizes); 67   68             try { 69                 FileWriter fw = new FileWriter(initcap(tablename) + ".java"); 70   71                 PrintWriter pw = new PrintWriter(fw); 72                 pw.println(content); 73                 pw.flush(); 74                 pw.close(); 75             } catch (IOException e) { 76                 e.printStackTrace(); 77             } 78         } catch (SQLException e) { 79             e.printStackTrace(); 80         } finally { 81             ConnectionFactory.getInstance().closeConnection(conn, pstmt, null); 82             rsmd = null; 83         } 84     } 85   86     /** 87      *    获取当前数据中的表名称 88      * @methodName getTablesName 89      * @time 2015年9月29日下午4:52:26 90      * @packageName fanshe 91      */ 92     public List
     
       getTablesName(){ 93         List
      
        list = null; 94         Connection conn = null; 95         DatabaseMetaData md = null; 96         ResultSet rs = null; 97         conn = ConnectionFactory.getInstance().getConnection(); 98         try { 99             md = conn.getMetaData();100             rs = md.getTables(null, null, null, null);101             if(rs!=null&&rs.next()){102                 list = new ArrayList
       
        ();103             }104             while (rs.next()) {105                 //System.out.println("|表"+(i++)+":"+rs.getString("TABLE_NAME"));106                 String tableName = rs.getString("TABLE_NAME");107                 list.add(tableName);108             }109  110         } catch (SQLException e) {111             e.printStackTrace();112         } finally {113             ConnectionFactory.getInstance().closeConnection(conn, null, rs);114             md = null;115         }116         return list;117     }118  119     /**120      * 解析处理(生成实体类主体代码)121      */122     private String parse(String[] colNames, String[] colTypes, int[] colSizes) {123         StringBuffer sb = new StringBuffer();124         if (f_util) {125             sb.append("import java.util.Date;\r\n");126         }127         if (f_sql) {128             sb.append("import java.sql.*;\r\n\r\n\r\n");129         }130         sb.append("public class " + initcap(tablename) + " {\r\n");131         processAllAttrs(sb);132         processAllMethod(sb);133         sb.append("}\r\n");134  135         //markerBean(initcap(tablename), sb.toString());136  137         return sb.toString();138  139     }140  141     /**142      *  创建java 文件  将生成的属性 get/set 方法 保存到 文件中143      * markerBean144      * @time 2015年9月29日下午4:15:22145      * @packageName fanshe146      * @param className  类名称147      * @param content    类内容  包括属性 getset 方法148      */149     public void markerBean(String className, String content) {150         String folder = System.getProperty("user.dir") + "/src/fanshe/";151  152         File file = new File(folder);153         if (!file.exists()) {154             file.mkdirs();155         }156         String fileName = folder + className + ".java";157  158         try {159             File newdao = new File(fileName);160             FileWriter fw = new FileWriter(newdao);161             fw.write(content);162             fw.flush();163             fw.close();164         } catch (IOException e) {165             e.printStackTrace();166         }167     }168  169     /**170      * 生成所有的方法171      *172      * @param sb173      */174     private void processAllMethod(StringBuffer sb) {175         for (int i = 0; i < colnames.length; i++) {176             sb.append("\tpublic void set" + initcap(colnames[i]) + "("177                     + sqlType2JavaType(colTypes[i]) + " " + colnames[i]178                     + "){\r\n");179             sb.append("\t\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");180             sb.append("\t}\r\n");181  182             sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get"183                     + initcap(colnames[i]) + "(){\r\n");184             sb.append("\t\treturn " + colnames[i] + ";\r\n");185             sb.append("\t}\r\n");186         }187     }188  189     /**190      * 解析输出属性191      *192      * @return193      */194     private void processAllAttrs(StringBuffer sb) {195         for (int i = 0; i < colnames.length; i++) {196             sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " "197                     + colnames[i] + ";\r\n");198  199         }200     }201  202     /**203      * 把输入字符串的首字母改成大写204      *205      * @param str206      * @return207      */208     private String initcap(String str) {209         char[] ch = str.toCharArray();210         if (ch[0] >= 'a' && ch[0] <= 'z') {211             ch[0] = (char) (ch[0] - 32);212         }213         return new String(ch);214     }215  216     private String sqlType2JavaType(String sqlType) {217         if (sqlType.equalsIgnoreCase("bit")) {218             return "bool";219         } else if (sqlType.equalsIgnoreCase("tinyint")) {220             return "byte";221         } else if (sqlType.equalsIgnoreCase("smallint")) {222             return "short";223         } else if (sqlType.equalsIgnoreCase("int")) {224             return "int";225         } else if (sqlType.equalsIgnoreCase("bigint")) {226             return "long";227         } else if (sqlType.equalsIgnoreCase("float")) {228             return "float";229         } else if (sqlType.equalsIgnoreCase("decimal")230                 || sqlType.equalsIgnoreCase("numeric")231                 || sqlType.equalsIgnoreCase("real")) {232             return "double";233         } else if (sqlType.equalsIgnoreCase("money")234                 || sqlType.equalsIgnoreCase("smallmoney")) {235             return "double";236         } else if (sqlType.equalsIgnoreCase("varchar")237                 || sqlType.equalsIgnoreCase("char")238                 || sqlType.equalsIgnoreCase("nvarchar")239                 || sqlType.equalsIgnoreCase("nchar")) {240             return "String";241         } else if (sqlType.equalsIgnoreCase("datetime")) {242             return "Date";243         }244  245         else if (sqlType.equalsIgnoreCase("image")) {246             return "Blob";247         } else if (sqlType.equalsIgnoreCase("text")) {248             return "Clob";249         }250         return null;251     }252  253     public static void main(String[] args) {254         new GenEntityTool();255     }256 }

获取当前数据库中所有的表

1     /** 2      *    获取当前数据中的表名称 3      * @methodName getTablesName 4      * @time 2015年9月29日下午4:52:26 5      * @packageName fanshe 6      */ 7     public List
     
       getTablesName(){ 8         List
      
        list = null; 9         Connection conn = null;10         DatabaseMetaData md = null;11         ResultSet rs = null;12         conn = ConnectionFactory.getInstance().getConnection();13         try {14             md = conn.getMetaData();15             rs = md.getTables(null, null, null, null);16             if(rs!=null&&rs.next()){17                 list = new ArrayList
       
        ();18             }19             while (rs.next()) {20                 //System.out.println("|表"+(i++)+":"+rs.getString("TABLE_NAME"));21                 String tableName = rs.getString("TABLE_NAME");22                 list.add(tableName);23             }24             25         } catch (SQLException e) {26             e.printStackTrace();27         } finally {28             ConnectionFactory.getInstance().closeConnection(conn, null, rs);29             md = null;30         }31         return list;32     }