我用javac checkUser.java后出现:
Note:checkUser.java uses unchecked or unsafe operations.
Note:Recompile with -Xlint :unchecked for details.
后用javac -xlint checkUser.java
---------------------------------------------------------------------------------------
checkUser.java:171:warning :[unchecked] unchecked call to add(E) as a member of the raw type java.util.Collection
result.add(qry);
^
checkUser.java:9:warning :[serial] serializable class com.checkUser has no definition of serialVersionUID
public class checkUser
^
2 warnings
------------------------------------------------------
我怀疑是我的这段代码中的Collection 有问题哪位帮我看下:
protected Collection getScore() {
String sql="select ";
sql+=user.getClassId()+".scoretime as scoretime,"+user.getClassId()+".scoreexam as scoreexam,";
sql+=user.getClassId()+".scoresum as scoresum,"+user.getClassId()+".studytype as studytype,";
sql+="course.courseid as courseid,course.coursename as coursename,course.coursevalue as coursevalue,";
sql+="course.coursetime as coursetime,courseteacher.userid as teacher,courseteacher.term as term ";
sql+=" from course join "+user.getClassId()+" on "+user.getClassId()+".courseid=course.courseid";
sql+=" join Courseteacher on course.courseid=Courseteacher.courseid where ";
sql+=user.getClassId()+".userid='"+user.getUserId()+"'";
Connection con=null;
try {
con = ConnDatabase.getConnection();
}
catch (Exception e) {
e.printStackTrace();
}
Statement stm=null;
ResultSet rs=null;
/**
* 返回查询的所有结果
*/
//------------------------------------
Collection result=new ArrayList();
try{
stm = con.createStatement();
rs = stm.executeQuery(sql); /**
* 读取查询到的每个结果放到arraylist中发送到页面
*/
while(rs.next()){
/**
* 存放每条记录的结果
*/
Query qry=new Query();
/**
* 记录每个查询到的单元
*/
qry.setCourseId(rs.getString("courseid"));
qry.setCourseName(rs.getString("coursename"));
qry.setCourseTime(rs.getInt("coursetime"));
qry.setCourseValue(rs.getFloat("coursevalue"));
qry.setScoreExam(rs.getInt("scoreexam"));
qry.setScoreSum(rs.getInt("scoresum"));
qry.setScoreTime(rs.getInt("scoretime"));
qry.setStudyType(rs.getString("studytype"));
qry.setTeacher(rs.getString("teacher"));
qry.setTerm(rs.getString("term"));
//---------------------------------------我怀疑是这里
result.add(qry);
}
return result;
}catch(SQLException e){
e.printStackTrace();
}
return null;
}
Note:checkUser.java uses unchecked or unsafe operations.
Note:Recompile with -Xlint :unchecked for details.
后用javac -xlint checkUser.java
---------------------------------------------------------------------------------------
checkUser.java:171:warning :[unchecked] unchecked call to add(E) as a member of the raw type java.util.Collection
result.add(qry);
^
checkUser.java:9:warning :[serial] serializable class com.checkUser has no definition of serialVersionUID
public class checkUser
^
2 warnings
------------------------------------------------------
我怀疑是我的这段代码中的Collection 有问题哪位帮我看下:
protected Collection getScore() {
String sql="select ";
sql+=user.getClassId()+".scoretime as scoretime,"+user.getClassId()+".scoreexam as scoreexam,";
sql+=user.getClassId()+".scoresum as scoresum,"+user.getClassId()+".studytype as studytype,";
sql+="course.courseid as courseid,course.coursename as coursename,course.coursevalue as coursevalue,";
sql+="course.coursetime as coursetime,courseteacher.userid as teacher,courseteacher.term as term ";
sql+=" from course join "+user.getClassId()+" on "+user.getClassId()+".courseid=course.courseid";
sql+=" join Courseteacher on course.courseid=Courseteacher.courseid where ";
sql+=user.getClassId()+".userid='"+user.getUserId()+"'";
Connection con=null;
try {
con = ConnDatabase.getConnection();
}
catch (Exception e) {
e.printStackTrace();
}
Statement stm=null;
ResultSet rs=null;
/**
* 返回查询的所有结果
*/
//------------------------------------
Collection result=new ArrayList();
try{
stm = con.createStatement();
rs = stm.executeQuery(sql); /**
* 读取查询到的每个结果放到arraylist中发送到页面
*/
while(rs.next()){
/**
* 存放每条记录的结果
*/
Query qry=new Query();
/**
* 记录每个查询到的单元
*/
qry.setCourseId(rs.getString("courseid"));
qry.setCourseName(rs.getString("coursename"));
qry.setCourseTime(rs.getInt("coursetime"));
qry.setCourseValue(rs.getFloat("coursevalue"));
qry.setScoreExam(rs.getInt("scoreexam"));
qry.setScoreSum(rs.getInt("scoresum"));
qry.setScoreTime(rs.getInt("scoretime"));
qry.setStudyType(rs.getString("studytype"));
qry.setTeacher(rs.getString("teacher"));
qry.setTerm(rs.getString("term"));
//---------------------------------------我怀疑是这里
result.add(qry);
}
return result;
}catch(SQLException e){
e.printStackTrace();
}
return null;
}
我的程序中的哪个函数是已经被废弃的呀!请明言,我新手