[英]j2me function java.lang.nullpointerexception - what is wrong in this?
Yesterday Night, i wrote this function to fetch all the tags from string containing xml data but something is not correct in this... Pls help... this function is returning java.lang.NullPointerException 昨天晚上,我编写了此函数来从包含xml数据的字符串中获取所有标签,但是在此中有些不正确...请帮助...该函数返回java.lang.NullPointerException
public void parseWebXML(String xd){
int i, j, k = 0;
String tagn, check = "";
int spos, epos;
byte[] len = xd.getBytes();
tags = new String[len.length*3/4];
int nextpos = 0;
for(i=0;i<len.length*3/4;i++){
spos = xd.indexOf("<", nextpos);
epos = xd.indexOf(">", spos);
tagn = xd.substring(spos, epos);
if(i == 0 || i == 1 || i == 2){
if(tagn.indexOf("/") == -1){
tags[k] = "<"+tagn+">";
k +=1;
}else{
continue;
}
}else{
if(tagn.indexOf("/") == -1){
for(j=0;j<tags.length;j++){
if(tags[i].equals(tags[j])){
check = "found";
}else{
check = "notfound";
}
}
if(check.equals("notfound")){
tags[i] = "<"+tagn+">";
k+=1;
}else{
continue;
}
}else{
continue;
}
}
nextpos = epos + 1;
}
}
error that i saw while executing in debugger mode 在调试器模式下执行时看到的错误
TRACE: <at java.lang.NullPointerException: 0>, Exception caught in Display class
java.lang.NullPointerException: 0
- httpcon.parseWebXML(), bci=170
tags[] has only 3 items. tags []只有3个项目。
if(i == 0 || i == 1 || i == 2){
if(tagn.indexOf("/") == -1){
tags[k] = "<"+tagn+">";
k +=1;
if i > 3 than tags[i] return null. 如果i> 3大于tag [i],则返回null。 And tags[i].equals throw NPE
和标签[i]。等于抛出NPE
您初始化了tag [],但未初始化其每个单元,因此tags[i].equals(tags[j])
可能导致了NPE
( tags[i]
为null)。
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