import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class BasicDao {
private static Connection con = null;
private static PreparedStatement ps = null;
private static ResultSet rs = null;
public static <T> List<T> selectAll(Class<T> clazz, String sql, Object parameter) {
List<T> result = new ArrayList<T>();
// 遍历parameter的所有属性和值作为参数
Field[] paramField = parameter.getClass().getDeclaredFields();
for (Field pf : paramField) {
try {
if (pf.getType() == String.class) {
if (pf.get(parameter) != null) {
sql = sql.replace("/*" + pf.getName() + "*/", "'" + pf.get(parameter).toString() + "'");
}
} else {
if (pf.get(parameter) != null) {
sql = sql.replace("/*" + pf.getName() + "*/", pf.get(parameter).toString());
}
}
System.out.println(pf.getName() + ":" + pf.get(parameter));
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
try {
con = DBConnection.ConnectDB();
ps = con.prepareStatement(sql);
System.out.println("[sql]:" + ps.toString().substring(ps.toString().indexOf(" ")));
rs = ps.executeQuery();
while (rs.next()) {
T entity;
try {
entity = clazz.newInstance();
} catch (Exception e) {
e.printStackTrace();
return result;
}
Field[] entityFiled = clazz.getFields();
int fieldCount = 0;
for (Field ef : entityFiled) {
// 根据字段取出对应set方法赋值
Method m;
try {
m = entity.getClass().getMethod(
"set" + ef.getName().substring(0, 1).toUpperCase() + ef.getName().substring(1),
ef.getType());
if (ef.getType() == Integer.class) {
m.invoke(entity, rs.getInt(++fieldCount));
} else if (ef.getType() == Long.class) {
m.invoke(entity, rs.getLong(++fieldCount));
} else if (ef.getType() == Double.class) {
m.invoke(entity, rs.getDouble(++fieldCount));
} else if (ef.getType() == Date.class) {
m.invoke(entity, rs.getDate(++fieldCount));
} else if (ef.getType() == String.class) {
m.invoke(entity, rs.getString(++fieldCount));
} // TODO
} catch (Exception e) {
e.printStackTrace();
return result;
}
}
result.add(entity);
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
}
