/**
*
*/
package cn.org.zeronote.orm.dao.parser;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import cn.org.zeronote.orm.ORMAutoAssemble;
import cn.org.zeronote.orm.ORMColumn;
import cn.org.zeronote.orm.ORMTable;
/**
* Orm sql语句生成
* @author <a href='mailto:lizheng8318@gmail.com'>lizheng</a>
*
*/
public class SqlSelGenerator implements Generator {
/** orm fields cache*/
private transient static Map<Class<?>, Map<Field, ORMColumn>> fieldsCache = new HashMap<Class<?>, Map<Field,ORMColumn>>();
private transient byte[] synObj = new byte[0];
/**ORM pojo class*/
protected Class<?> pojoClazz;
protected Map<String, Object[]> argsMap;
protected String sql;
protected Object[] args;
/**
*
*/
public SqlSelGenerator() {
}
/**
*
* @param pojoClazz pojo class
* @param args params
*/
public SqlSelGenerator(Class<?> pojoClazz, Map<String, Object[]> args) {
this.pojoClazz = pojoClazz;
this.argsMap = args;
}
/**
* 生成SQL
* @throws IllegalAccessException exception
*/
protected void generateParam() throws IllegalAccessException {
ORMAutoAssemble ormaa = pojoClazz.getAnnotation(ORMAutoAssemble.class);
if (ormaa == null) {
throw new IllegalAccessException("It not a ORMAutoAssemble Class!");
}
ORMTable ormTable = pojoClazz.getAnnotation(ORMTable.class);
if (ormTable == null) {
throw new IllegalAccessException("It not a ORMTable Class!");
}
String tableName = ormTable.tableName();
String[] orders = ormTable.order();
List<Object> params = new ArrayList<Object>();
this.sql = genSql(params, tableName, this.argsMap, orders);
// params
this.args = params.toArray();
}
/**
* 生成sql
* @param params params
* @param tableName table name
* @param argsMap arg map
* @param orders order
* @return the sql
*/
protected String genSql(List<Object> params, String tableName, Map<String, Object[]> argsMap, String[] orders) {
// params to param:params
StringBuilder sql = new StringBuilder("SELECT ");
// SELECT
Field[] fields = pojoClazz.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
ORMColumn ormc = getAnnotation(pojoClazz, field);
if (ormc != null) {
sql.append(ormc.value()).append(",");
}
}
sql.replace(sql.length() - 1, sql.length(), " ");
// FROM
sql.append("FROM ").append(tableName).append(" ");
// WHERE
if (argsMap != null && argsMap.size() > 0) {
sql.append("WHERE (");
for (Field field : fields) {
field.setAccessible(true);
ORMColumn ormc = getAnnotation(pojoClazz, field);
if (ormc != null) {
Object[] val = argsMap.get(field.getName());
if (val != null) {
if (val.length > 1) {
// 多参数
sql.append("(");
for (Object ovl : val) {
sql.append(ormc.value()).append("=? OR ");
Class<?> tc = field.getDeclaringClass();
params.add(matchParam(ovl, tc));
}
sql.delete(sql.length() - 3, sql.length());
sql.append(") AND ");
} else {
// 单参数
sql.append(ormc.value()).append("=? AND ");
Class<?> tc = field.getDeclaringClass();
params.add(matchParam(val[0], tc));
}
}
}
}
sql.replace(sql.length() - 5, sql.length(), ") ");
}
// ORDER
if (orders != null && orders.length > 0) {
sql.append("ORDER BY ");
for (String order : orders) {
sql.append(order).append(",");
}
sql.delete(sql.length() - 1, sql.length());
}
// return
return sql.toString();
}
// 缓存annotation
private ORMColumn getAnnotation(Class<?> clz, Field field) {
Map<Field, ORMColumn> fs = fieldsCache.get(clz);
if (fs == null) {
// 加载
synchronized (synObj) {
fs = fieldsCache.get(clz);
if (fs == null) {
fs = new HashMap<Field, ORMColumn>();
Field[] fields = pojoClazz.getDeclaredFields();
for (Field f : fields) {
f.setAccessible(true);
ORMColumn ormc = f.getAnnotation(ORMColumn.class);
fs.put(f, ormc);
}
fieldsCache.put(clz, fs);
}
}
}
return fs.get(field);
}
/**
* 类型匹配转换
* 如果val与给定的clz不匹配，则返回精确转换后的val
* 转换原则：
* String ->Number
* Number -> String
* @param val val
* @param clz class
* @return the value obj
*/
private Object matchParam(Object val, Class<?> clz) {
if (val == null) {
return val;
}
if (String.class.equals(clz)) {
// 目标为String
return val.toString();
} else if (Integer.class.equals(clz) || int.class.equals(clz)) {
// 目标int
return val instanceof Integer ? val : Integer.parseInt(val.toString());
} else if (Long.class.equals(clz) || long.class.equals(clz)) {
// 目标long
return val instanceof Long ? val : Long.parseLong(val.toString());
} else if (Double.class.equals(clz) || double.class.equals(clz)) {
// 目标Double
return val instanceof Double ? val : Double.parseDouble(val.toString());
} else if (Float.class.equals(clz) || float.class.equals(clz)) {
// 目标Float
return val instanceof Float ? val : Float.parseFloat(val.toString());
} else {
// 其它不转换
return val;
}
}
/**
* 相关参数
* @return the args
* @throws IllegalAccessException exception
*/
public Object[] getArgs() throws IllegalAccessException {
if (args == null) {
generateParam();
}
return args == null ? new Object[0] : args;
}
/**
* Sql语句
* @return the sql
* @throws IllegalAccessException exception
*/
public String getSql() throws IllegalAccessException {
if (sql == null) {
generateParam();
}
return sql;
}
/**
* @return the pojoClazz
*/
public Class<?> getPojoClazz() {
return pojoClazz;
}
/**
* @param pojoClazz the pojoClazz to set
*/
public void setPojoClazz(Class<?> pojoClazz) {
this.pojoClazz = pojoClazz;
}
}