java 从数据库表反射出实体类，自动生成实体类
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01.package com.db.gen.entity.tool;
02.
03.
04.import java.io.File;
05.import java.io.FileWriter;
06.import java.io.IOException;
07.import java.io.PrintWriter;
08.import java.sql.Connection;
09.import java.sql.DriverManager;
10.import java.sql.PreparedStatement;
11.import java.sql.ResultSetMetaData;
12.import java.sql.SQLException;
13.import java.util.Date;
14.
15.public class GenEntityMysql {
16.
17. private String packageOutPath = "com.user.entity";//指定实体生成所在包的路径
18. private String authorName = "封狼居胥";//作者名字
19. private String tablename = "user";//表名
20. private String[] colnames; // 列名数组
21. private String[] colTypes; //列名类型数组
22. private int[] colSizes; //列名大小数组
23. private boolean f_util = false; // 是否需要导入包java.util.*
24. private boolean f_sql = false; // 是否需要导入包java.sql.*
25.
26. //数据库连接
27. private static final String URL ="jdbc:mysql://localhost:3306/jbpm";
28. private static final String NAME = "root";
29. private static final String PASS = "root";
30. private static final String DRIVER ="com.mysql.jdbc.Driver";
31.
32. /*
33. * 构造函数
34. */
35. public GenEntityMysql(){
36. //创建连接
37. Connection con;
38. //查要生成实体类的表
39. String sql = "select * from " + tablename;
40. PreparedStatement pStemt = null;
41. try {
42. try {
43. Class.forName(DRIVER);
44. } catch (ClassNotFoundException e1) {
45. // TODO Auto-generated catch block
46. e1.printStackTrace();
47. }
48. con = DriverManager.getConnection(URL,NAME,PASS);
49. pStemt = con.prepareStatement(sql);
50. ResultSetMetaData rsmd = pStemt.getMetaData();
51. int size = rsmd.getColumnCount(); //统计列
52. colnames = new String[size];
53. colTypes = new String[size];
54. colSizes = new int[size];
55. for (int i = 0; i < size; i++) {
56. colnames[i] = rsmd.getColumnName(i + 1);
57. colTypes[i] = rsmd.getColumnTypeName(i + 1);
58.
59. if(colTypes[i].equalsIgnoreCase("datetime")){
60. f_util = true;
61. }
62. if(colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text")){
63. f_sql = true;
64. }
65. colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
66. }
67.
68. String content = parse(colnames,colTypes,colSizes);
69.
70. try {
71. File directory = new File("");
72. //System.out.println("绝对路径："+directory.getAbsolutePath());
73. //System.out.println("相对路径："+directory.getCanonicalPath());
74. String path=this.getClass().getResource("").getPath();
75.
76. System.out.println(path);
77. System.out.println("src/?/"+path.substring(path.lastIndexOf("/com/", path.length())) );
78.// String outputPath = directory.getAbsolutePath()+ "/src/"+path.substring(path.lastIndexOf("/com/", path.length()), path.length()) + initcap(tablename) + ".java";
79. String outputPath = directory.getAbsolutePath()+ "/src/"+this.packageOutPath.replace(".", "/")+"/"+initcap(tablename) + ".java";
80. FileWriter fw = new FileWriter(outputPath);
81. PrintWriter pw = new PrintWriter(fw);
82. pw.println(content);
83. pw.flush();
84. pw.close();
85. } catch (IOException e) {
86. e.printStackTrace();
87. }
88.
89. } catch (SQLException e) {
90. e.printStackTrace();
91. } finally{
92.// try {
93.// con.close();
94.// } catch (SQLException e) {
95.// // TODO Auto-generated catch block
96.// e.printStackTrace();
97.// }
98. }
99. }
100.
101. /**
102. * 功能：生成实体类主体代码
103. * @param colnames
104. * @param colTypes
105. * @param colSizes
106. * @return
107. */
108. private String parse(String[] colnames, String[] colTypes, int[] colSizes) {
109. StringBuffer sb = new StringBuffer();
110.
111. //判断是否导入工具包
112. if(f_util){
113. sb.append("import java.util.Date;\r\n");
114. }
115. if(f_sql){
116. sb.append("import java.sql.*;\r\n");
117. }
118. sb.append("package " + this.packageOutPath + ";\r\n");
119. sb.append("\r\n");
120. //注释部分
121. sb.append(" /**\r\n");
122. sb.append(" * "+tablename+" 实体类\r\n");
123. sb.append(" * "+new Date()+" "+this.authorName+"\r\n");
124. sb.append(" */ \r\n");
125. //实体部分
126. sb.append("\r\n\r\npublic class " + initcap(tablename) + "{\r\n");
127. processAllAttrs(sb);//属性
128. processAllMethod(sb);//get set方法
129. sb.append("}\r\n");
130.
131. //System.out.println(sb.toString());
132. return sb.toString();
133. }
134.
135. /**
136. * 功能：生成所有属性
137. * @param sb
138. */
139. private void processAllAttrs(StringBuffer sb) {
140.
141. for (int i = 0; i < colnames.length; i++) {
142. sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
143. }
144.
145. }
146.
147. /**
148. * 功能：生成所有方法
149. * @param sb
150. */
151. private void processAllMethod(StringBuffer sb) {
152.
153. for (int i = 0; i < colnames.length; i++) {
154. sb.append("\tpublic void set" + initcap(colnames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " " +
155. colnames[i] + "){\r\n");
156. sb.append("\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");
157. sb.append("\t}\r\n");
158. sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + initcap(colnames[i]) + "(){\r\n");
159. sb.append("\t\treturn " + colnames[i] + ";\r\n");
160. sb.append("\t}\r\n");
161. }
162.
163. }
164.
165. /**
166. * 功能：将输入字符串的首字母改成大写
167. * @param str
168. * @return
169. */
170. private String initcap(String str) {
171.
172. char[] ch = str.toCharArray();
173. if(ch[0] >= 'a' && ch[0] <= 'z'){
174. ch[0] = (char)(ch[0] - 32);
175. }
176.
177. return new String(ch);
178. }
179.
180. /**
181. * 功能：获得列的数据类型
182. * @param sqlType
183. * @return
184. */
185. private String sqlType2JavaType(String sqlType) {
186.
187. if(sqlType.equalsIgnoreCase("bit")){
188. return "boolean";
189. }else if(sqlType.equalsIgnoreCase("tinyint")){
190. return "byte";
191. }else if(sqlType.equalsIgnoreCase("smallint")){
192. return "short";
193. }else if(sqlType.equalsIgnoreCase("int")){
194. return "int";
195. }else if(sqlType.equalsIgnoreCase("bigint")){
196. return "long";
197. }else if(sqlType.equalsIgnoreCase("float")){
198. return "float";
199. }else if(sqlType.equalsIgnoreCase("decimal") || sqlType.equalsIgnoreCase("numeric")
200. || sqlType.equalsIgnoreCase("real") || sqlType.equalsIgnoreCase("money")
201. || sqlType.equalsIgnoreCase("smallmoney")){
202. return "double";
203. }else if(sqlType.equalsIgnoreCase("varchar") || sqlType.equalsIgnoreCase("char")
204. || sqlType.equalsIgnoreCase("nvarchar") || sqlType.equalsIgnoreCase("nchar")
205. || sqlType.equalsIgnoreCase("text")){
206. return "String";
207. }else if(sqlType.equalsIgnoreCase("datetime")){
208. return "Date";
209. }else if(sqlType.equalsIgnoreCase("image")){
210. return "Blod";
211. }
212.
213. return null;
214. }
215.
216. /**
217. * 出口
218. * TODO
219. * @param args
220. */
221. public static void main(String[] args) {
222.
223. new GenEntityMysql();
224.
225. }
226.
227.}
01.package com.db.gen.entity.tool;
02.
03.
04.import java.io.File;
05.import java.io.FileWriter;
06.import java.io.IOException;
07.import java.io.PrintWriter;
08.import java.sql.Connection;
09.import java.sql.DriverManager;
10.import java.sql.PreparedStatement;
11.import java.sql.ResultSet;
12.import java.sql.ResultSetMetaData;
13.import java.sql.SQLException;
14.import java.sql.Statement;
15.import java.util.Date;
16.
17.public class GenEntityOracle {
18.
19. private String packageOutPath = "com.user.entity";//指定实体生成所在包的路径
20. private String authorName = "封狼居胥";//作者名字
21. private String tablename = "emp";//表名
22. private String[] colnames; // 列名数组
23. private String[] colTypes; //列名类型数组
24. private int[] colSizes; //列名大小数组
25. private boolean f_util = false; // 是否需要导入包java.util.*
26. private boolean f_sql = false; // 是否需要导入包java.sql.*
27.
28. //数据库连接
29. private static final String URL ="jdbc:oracle:thin:@127.0.0.1:1521:ORCL";
30. private static final String NAME = "scrot";
31. private static final String PASS = "tiger";
32. private static final String DRIVER ="oracle.jdbc.driver.OracleDriver";
33.
34. /*
35. * 构造函数
36. */
37. public GenEntityOracle(){
38. //创建连接
39. Connection con;
40. //查要生成实体类的表
41. String sql = "select * from " + tablename;
42. Statement pStemt = null;
43. try {
44. try {
45. Class.forName(DRIVER);
46. } catch (ClassNotFoundException e1) {
47. // TODO Auto-generated catch block
48. e1.printStackTrace();
49. }
50. con = DriverManager.getConnection(URL,NAME,PASS);
51. pStemt = (Statement) con.createStatement();
52. ResultSet rs = pStemt.executeQuery(sql);
53. ResultSetMetaData rsmd = rs.getMetaData();
54. int size = rsmd.getColumnCount(); //统计列
55. colnames = new String[size];
56. colTypes = new String[size];
57. colSizes = new int[size];
58. for (int i = 0; i < size; i++) {
59. colnames[i] = rsmd.getColumnName(i + 1);
60. colTypes[i] = rsmd.getColumnTypeName(i + 1);
61.
62. if(colTypes[i].equalsIgnoreCase("date") || colTypes[i].equalsIgnoreCase("timestamp")){
63. f_util = true;
64. }
65. if(colTypes[i].equalsIgnoreCase("blob") || colTypes[i].equalsIgnoreCase("char")){
66. f_sql = true;
67. }
68. colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
69. }
70.
71. String content = parse(colnames,colTypes,colSizes);
72.
73. try {
74. File directory = new File("");
75. //System.out.println("绝对路径："+directory.getAbsolutePath());
76. //System.out.println("相对路径："+directory.getCanonicalPath());
77. String path=this.getClass().getResource("").getPath();
78.
79. System.out.println(path);
80. System.out.println("src/?/"+path.substring(path.lastIndexOf("/com/", path.length())) );
81.// String outputPath = directory.getAbsolutePath()+ "/src/"+path.substring(path.lastIndexOf("/com/", path.length()), path.length()) + initcap(tablename) + ".java";
82. String outputPath = directory.getAbsolutePath()+ "/src/"+this.packageOutPath.replace(".", "/")+"/"+initcap(tablename) + ".java";
83. FileWriter fw = new FileWriter(outputPath);
84. PrintWriter pw = new PrintWriter(fw);
85. pw.println(content);
86. pw.flush();
87. pw.close();
88. } catch (IOException e) {
89. e.printStackTrace();
90. }
91.
92. } catch (SQLException e) {
93. e.printStackTrace();
94. } finally{
95.// try {
96.// con.close();
97.// } catch (SQLException e) {
98.// // TODO Auto-generated catch block
99.// e.printStackTrace();
100.// }
101. }
102. }
103.
104. /**
105. * 功能：生成实体类主体代码
106. * @param colnames
107. * @param colTypes
108. * @param colSizes
109. * @return
110. */
111. private String parse(String[] colnames, String[] colTypes, int[] colSizes) {
112. StringBuffer sb = new StringBuffer();
113.
114. //判断是否导入工具包
115. if(f_util){
116. sb.append("import java.util.Date;\r\n");
117. }
118. if(f_sql){
119. sb.append("import java.sql.*;\r\n");
120. }
121. sb.append("package " + this.packageOutPath + ";\r\n");
122. sb.append("\r\n");
123. //注释部分
124. sb.append(" /**\r\n");
125. sb.append(" * "+tablename+" 实体类\r\n");
126. sb.append(" * "+new Date()+" "+this.authorName+"\r\n");
127. sb.append(" */ \r\n");
128. //实体部分
129. sb.append("\r\n\r\npublic class " + initcap(tablename) + "{\r\n");
130. processAllAttrs(sb);//属性
131. processAllMethod(sb);//get set方法
132. sb.append("}\r\n");
133.
134. //System.out.println(sb.toString());
135. return sb.toString();
136. }
137.
138. /**
139. * 功能：生成所有属性
140. * @param sb
141. */
142. private void processAllAttrs(StringBuffer sb) {
143.
144. for (int i = 0; i < colnames.length; i++) {
145. sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
146. }
147.
148. }
149.
150. /**
151. * 功能：生成所有方法
152. * @param sb
153. */
154. private void processAllMethod(StringBuffer sb) {
155.
156. for (int i = 0; i < colnames.length; i++) {
157. sb.append("\tpublic void set" + initcap(colnames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " " +
158. colnames[i] + "){\r\n");
159. sb.append("\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");
160. sb.append("\t}\r\n");
161. sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + initcap(colnames[i]) + "(){\r\n");
162. sb.append("\t\treturn " + colnames[i] + ";\r\n");
163. sb.append("\t}\r\n");
164. }
165.
166. }
167.
168. /**
169. * 功能：将输入字符串的首字母改成大写
170. * @param str
171. * @return
172. */
173. private String initcap(String str) {
174.
175. char[] ch = str.toCharArray();
176. if(ch[0] >= 'a' && ch[0] <= 'z'){
177. ch[0] = (char)(ch[0] - 32);
178. }
179.
180. return new String(ch);
181. }
182.
183. /**
184. * 功能：获得列的数据类型
185. * @param sqlType
186. * @return
187. */
188. private String sqlType2JavaType(String sqlType) {
189.
190. if(sqlType.equalsIgnoreCase("binary_double")){
191. return "double";
192. }else if(sqlType.equalsIgnoreCase("binary_float")){
193. return "float";
194. }else if(sqlType.equalsIgnoreCase("blob")){
195. return "byte[]";
196. }else if(sqlType.equalsIgnoreCase("blob")){
197. return "byte[]";
198. }else if(sqlType.equalsIgnoreCase("char") || sqlType.equalsIgnoreCase("nvarchar2")
199. || sqlType.equalsIgnoreCase("varchar2")){
200. return "String";
201. }else if(sqlType.equalsIgnoreCase("date") || sqlType.equalsIgnoreCase("timestamp")
202. || sqlType.equalsIgnoreCase("timestamp with local time zone")
203. || sqlType.equalsIgnoreCase("timestamp with time zone")){
204. return "Date";
205. }else if(sqlType.equalsIgnoreCase("number")){
206. return "Long";
207. }
208.
209. return "String";
210. }
211.
212. /**
213. * 出口
214. * TODO
215. * @param args
216. */
217. public static void main(String[] args) {
218.
219. new GenEntityOracle();
220.
221. }
222.
223.}
