QueryRunner run = new QueryRunner(dataSource);// Use the BeanHandler implementation to convert the first// ResultSet row into a Person JavaBean.ResultSetHandler<Person> h = new BeanHandler<Person>(Person.class);// Execute the SQL statement with one replacement parameter and// return the results in a new Person object generated by the BeanHandler.Person p = run.query( "SELECT * FROM Person WHERE name=?", h, "John Doe");榪欓噷鏈変釜鍦版柟鏈夌害鏉燂紝灝辨槸瑕佹眰紺轟緥涓殑JavaBean綾籔erson涓殑瀛楁瀹氫箟瑕佸拰鏁版嵁搴撶殑瀛楁瀹氫箟涓鑷淬侸ava鐨勫懡鍚嶄範鎯竴鑸槸楠嗗嘲鍐欐硶錛屼緥濡倁serId錛岄偅涔堟暟鎹簱涓氨蹇呴』瀹氫箟涓簎serId錛岃岄棶棰樺湪浜庯細鏈夋椂鍊欐垜浠渶瑕佹暟鎹簱涓瓧孌電殑瀹氫箟鏍煎紡涓嶫avaBean鐨勫懡鍚嶄笉涓鏍鳳紝姣斿鏁版嵁搴撳畾涔変負錛歶ser_id錛岃孞avaBean鍒欏畾涔変負userId
鐪嬫簮浠ｇ爜鍙兘鏈夌偣璐規椂闂達紝鍦ㄥ畼鏂圭殑example欏甸潰鐨勬渶涓嬮潰鏋滅劧鏈変竴孌靛叧浜庤嚜瀹氫箟BeanProcessor鐨勬寚寮曘傛憳褰曞嚭鏉ワ細
BasicRowProcessor uses a BeanProcessor to convert ResultSet columns into JavaBean properties. You can subclass and override processing steps to handle datatype mapping specific to your application. The provided implementation delegates datatype conversion to the JDBC driver.
BeanProcessor maps columns to bean properties as documented in the BeanProcessor.toBean() javadoc. Column names must match the bean's property names case insensitively. For example, the firstname column would be stored in the bean by calling its setFirstName() method. However, many database column names include characters that either can't be used or are not typically used in Java method names. You can do one of the following to map these columns to bean properties:
1. Alias the column names in the SQL so they match the Java names: select social_sec# as socialSecurityNumber from person
2. Subclass BeanProcessor and override the mapColumnsToProperties() method to strip out the offending characters.
澶ф鎰忔濆氨鏄彁渚涗簩縐嶆柟寮忥細涓縐嶅氨鏄渶鐩存帴鐨勶紝鐢╝s鍏抽敭瀛楁妸colName閲嶅懡鍚嶏紝鍙︿竴縐嶆柟寮忓氨鏄戶鎵緽eanProcessor綾伙紝閲嶅啓mapColumnsToProperties()鏂規硶銆?br /> 閭ｅ綋鐒舵槸絎簩縐嶆柟寮忔洿鍔犲叿鏈変唬琛ㄦс傚皾璇曚簡涓涓嬨備唬鐮佸涓嬶細
1
public class CustomBeanProcessor extends BeanProcessor {
2
3 @Override
4 protected int[] mapColumnsToProperties(ResultSetMetaData rsmd,
5
PropertyDescriptor[] props) throws SQLException {
6 int cols = rsmd.getColumnCount();
7 int columnToProperty[] = new int[cols + 1];
8 Arrays.fill(columnToProperty, PROPERTY_NOT_FOUND);
9
10 for (int col = 1; col <= cols; col++) {
11 String columnName = rsmd.getColumnLabel(col);
12 if (null == columnName || 0 == columnName.length()) {
13 columnName = rsmd.getColumnName(col);
14
}
15 columnName = colNameConvent(columnName); // 鍦ㄨ繖閲岃繘琛屾暟鎹簱琛╟olumnName鐨勭壒孌婂鐞?/span>
16 for (int i = 0; i < props.length; i++) {
17
18 if (columnName.equalsIgnoreCase(props[i].getName())) {
19 columnToProperty[col] = i;
20 break;
21 }
22 }
23 }
24 return columnToProperty;
25 }
26
27 /**
28 * 鏁版嵁搴撳垪鍚嶉噸鏂扮害瀹?br />
29 * @param columnName
30 * @return
31 */
32 private String colNameConvent(String columnName) {
33 String[] strs = columnName.split("_");
34 String conventName = "";
35 for (int i = 0; i < strs.length; i++) {
36 conventName += StringUtils.capitalize(strs[i]);
37 }
38 StringUtils.uncapitalize(conventName);
39 return conventName;
40 }
41
}
public class CustomBeanProcessor extends BeanProcessor {
2
3
@Override4
protected int[] mapColumnsToProperties(ResultSetMetaData rsmd,5
PropertyDescriptor[] props) throws SQLException {
PropertyDescriptor[] props) 6
int cols = rsmd.getColumnCount();7
int columnToProperty[] = new int[cols + 1];8
Arrays.fill(columnToProperty, PROPERTY_NOT_FOUND);9
10
for (int col = 1; col <= cols; col++) {11
String columnName = rsmd.getColumnLabel(col); 12
if (null == columnName || 0 == columnName.length()) {13
columnName = rsmd.getColumnName(col);14
}15
columnName = colNameConvent(columnName); // 鍦ㄨ繖閲岃繘琛屾暟鎹簱琛╟olumnName鐨勭壒孌婂鐞?/span>16
for (int i = 0; i < props.length; i++) {17
18
if (columnName.equalsIgnoreCase(props[i].getName())) {19
columnToProperty[col] = i;20
break;21
}22
}23
}24
return columnToProperty;25
}26
27
/**28
* 鏁版嵁搴撳垪鍚嶉噸鏂扮害瀹?br />
29 * @param columnName30
* @return31
*/32
private String colNameConvent(String columnName) {33
String[] strs = columnName.split("_");34
String conventName = "";35
for (int i = 0; i < strs.length; i++) {36
conventName += StringUtils.capitalize(strs[i]);37
}38
StringUtils.uncapitalize(conventName);39
return conventName;40
}41
}娉ㄦ剰mapColumnsToProperties鏂規硶鐨勯昏緫鏄粠鐖剁被鐨勬柟娉曚腑鐩存帴澶嶅埗鍑烘潵鐨勶紝鐒跺悗鍦ㄧ15琛岄偅閲屽彉浜嗕釜鎴忔硶錛岃繖閲岀殑columnName灝辨槸浠庢暟鎹簱涓鍑烘潵鐨勶紝鑷畾涔変竴涓猵rivate鏂規硶鐢ㄤ簬杞崲鍛藉悕錛岃繖閲屼綘灝卞彲浠ユ坊鍔犺嚜宸辯殑鍛藉悕綰︽潫銆備緥濡備笂闈㈠氨鏄妸 user_id 杞寲涓篔ava鐨勯獑宄板啓娉曪細userId
鍐嶆繁鍏ヤ竴灞傛濊冿紝浣犲彲浠ュ湪榪欓噷榪涜鏇村鎵╁睍錛屼互渚胯鑷繁鍙互閫夋嫨涓嶅悓鐨勫懡鍚嶈漿鎹㈡柟寮忋傚畾涔変簡榪欎釜Processor涔嬪悗錛屼笅闈㈢湅鐪嬪浣曡皟鐢細
Connection conn = ConnectionManager.getInstance().getConnection();QueryRunner qr = new QueryRunner();CustomBeanProcessor convert = new CustomBeanProcessor();RowProcessor rp = new BasicRowProcessor(convert);BeanHandler<User> bh = new BeanHandler<User>(User.class, rp);User u = qr.query(conn, sql, bh, params);DbUtils.close(conn); 1protected <T> List<T> selectBeanList(Connection conn, String sql, Class<T> type,
2 Object[] params) throws Exception {
3 log.debug("select sql:[" + sql + "]");
4 QueryRunner qr = new QueryRunner();
5 CustomBeanProcessor convert = new CustomBeanProcessor();
6 RowProcessor rp = new BasicRowProcessor(convert);
7 ResultSetHandler<List<T>> bh = new BeanListHandler<T>(type, rp);
8 List<T> list = qr.query(conn, sql, bh, params);
9 return list;
10 }
protected <T> List<T> selectBeanList(Connection conn, String sql, Class<T> type,2
Object[] params) throws Exception {3
log.debug("select sql:[" + sql + "]");4
QueryRunner qr = new QueryRunner();5
CustomBeanProcessor convert = new CustomBeanProcessor();6
RowProcessor rp = new BasicRowProcessor(convert);7
ResultSetHandler<List<T>> bh = new BeanListHandler<T>(type, rp);8
List<T> list = qr.query(conn, sql, bh, params);9
return list;10
}鑷充簬涓轟粈涔堟墿灞曡繖涓柟娉曞氨鍙互瀹炵幇榪欎釜閫昏緫灝卞緱鍘昏窡婧愪唬鐮佺湅瀹冪殑鍐呴儴瀹炵幇錛岀敤浜嗕竴浜汮avaBean鐨勫鐞嗗拰鍙嶆槧鐨勬妧宸ф潵鍋氱殑銆傚叿浣撳氨涓嶈銆?br /> 鎬葷粨錛歝ommons緇勪歡閮借璁″緱闈炲父濂斤紝鍙墿灞曟у拰瀹炵敤鎬ч兘闈炲父楂樸傝櫧鐒朵笂闈婦渚嬪疄鐜頒簡杞崲閫昏緫鐨勬浛鎹紝浣嗘槸浠嶇劧闇瑕佸紑鍙戜漢鍛樺湪璁捐鏁版嵁搴撶殑鏃跺欏拰鍐橨avaBean鏃墮兘瑕佷弗鏍煎仛濂借鑼冿紝閬垮厤浜х敓涓嶅繀瑕佺殑闂銆傝繖鏂歸潰Ruby On Rails灝辯洿鎺ュ唴閮ㄥ疄鐜幫紝鍔ㄦ佽璦鐨勪紭鐐圭壒鍒兘浣撶幇錛屽悓鏃跺己鍒朵綘鍦ㄨ璁℃椂蹇呴』鐢ㄨ繖縐嶆柟寮忥紝鍏稿瀷鐨勭害瀹氫紭浜庨厤緗師鍒欍傚綋鐒訛紝鍦╠butils閲屼綘鎰挎剰浜岀瀛楁鍚嶉兘涓鏍蜂篃鏃犲彲鍘氶潪銆?br /> 緙虹偣錛欱eanProcessor鏄笉鏀寔鍏寵仈鏌ヨ鐨勶紝鎵浠ヤ笂闈㈢殑鏂瑰紡涔熷彧鑳藉眬闄愪簬鍗曡〃鐨勮漿鎹紝榪欑偣灝變笉濡俶yBatis鍜孒ibernate錛屽綋鐒剁敤榪欎簩涓氨寮曞叆浜嗕竴浜涘鏉傛э紝濡備綍鏉冭 闇瑕佽嚜宸辮 閲忥紝鍝釜鐢ㄥ緱濂介兘涓鏍楓傛湰浜哄氨涓嶅枩嬈yBatis閭ｇ鎶奡QL鍐欏埌XML涓殑鏂瑰紡錛岃榪囧お澶嶆潅鐨凷QL鏈緇堝湪XML閲岄潰鍙樺緱闈㈢洰鍏ㄩ潪錛屽鏋滄槸鎺ユ墜鍒漢鐨勪唬鐮侊紝鏄緢鐥涜嫤鐨勶紝鑰屼笖浣犳棤娉曢伩鍏嶅彧淇敼XML鑰屼笉鏀笿ava錛屾棦鐒朵簩鑰呴兘瑕佹敼錛岄偅鐩存帴鍐橨ava閲屽張鏈変粈涔堝尯鍒紵綆鍗曞氨鏄編銆傛牸寮忓拰娉ㄩ噴鍐欏ソ涓鐐瑰悓鏍峰緢瀹規槗鐞嗚В錛?
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1public Map<String, Object> toMap(ResultSet rs) throws SQLException {
2 Map<String, Object> result = new CaseInsensitiveHashMap();
3 ResultSetMetaData rsmd = rs.getMetaData();
4 int cols = rsmd.getColumnCount();
5
6 for (int i = 1; i <= cols; i++) {
7 result.put(rsmd.getColumnName(i), rs.getObject(i));
8 }
9
10 return result;
11 }
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Map<String, Object> result = new CaseInsensitiveHashMap();3
ResultSetMetaData rsmd = rs.getMetaData();4
int cols = rsmd.getColumnCount();5
6
for (int i = 1; i <= cols; i++) {7
result.put(rsmd.getColumnName(i), rs.getObject(i));8
}9
10
return result;11
}AS 瀛愬彞鏉ユ寚瀹氥傚鏋滄湭鎸囧畾 SQL AS錛屽垯浠?getColumnLabel 榪斿洖鐨勫煎皢鍜?getColumnName 鏂規硶榪斿洖鐨勫肩浉鍚?/span>銆傝嚜宸辨墜鍔ㄨ瘯楠屼簡涓涓嬶紝鏋滅劧濡傛墍鏂欙紝闂灝卞嚭鍦ㄨ繖閲屻?br />
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