java实践过程中问题汇总1
正确事例：
package myown;
import java.lang.reflect.Array;
import java.net.*;
import java.util.ArrayList;
import java.util.Arrays;
//import java.util.Set;
//import java.util.StringTokenizer;
//import java.util.concurrent.ForkJoinPool.ManagedBlocker;
import java.io.*;
public class urlgetcontent {
/**
* @param args
*/
public static void main(String[] args) {
//System.out.println(arr);
process process=new process();
process.setcode("sh600000");
process.Settime("2013-02-08");
// System.out.println(process.gettime()); // the problem1
process.pracess();
}
}
class process
{
private String time;
private String code;
public void Settime(String time)
{
this.time=time;
}
public void setcode(String code)
{
this.code=code;
}
public String gettime()
{
return this.time;
}
public String getcode()
{
return this.code;
}
public void pracess() {
// TODO Auto-generated constructor stub
String arr[][]=null;
urlprocess processUrlprocess =new urlprocess();
arr= processUrlprocess.ReArray("http://market.finance.sina.com.cn/downxls.php?date="+this.time+"&symbol="+this.code);
System.out.println(Arrays.deepToString(arr));
}
}
class urlprocess
{
public ArrayList<String> urlprocess(String url) throws Exception
{
URL oracle = new URL(url);
BufferedReader in = new BufferedReader(
new InputStreamReader(oracle.openStream()));
String inputLine;
ArrayList<String> man=new ArrayList<String>();
while ((inputLine = in.readLine()) != null)
{
man.add(inputLine);
}
man.remove(0);
return man;
}
// #pointer
public String[][] ReArray(String url)
{
String[][] resultsa;
StringToArray sta=new StringToArray("\t");
try {
ArrayList<String> newurllist=urlprocess(url);
resultsa=new String[newurllist.size()][];
for (int i = 0; i <newurllist.size(); i++) {
resultsa[i]=sta.str2array((String)newurllist.get(i));
// results[i]= Arrays.copyOf(results[i], results[i].length+2);
// results[i][results.length-2]=process.getcode();
//results[i][results.length-1]=process.gettime();
}
//System.out.println(Arrays.deepToString(results));
return resultsa; ++++++++++
} catch (Exception e) {
// TODO: handle exception
}
return null; ++++++++++
}
}
class StringToArray {
private String split;
public StringToArray(String split)
{
this.split=split;
}
public String[] str2array(String s)
{
String str2array=s;
//1. First method with split()
// split(String Delimiter)
String[] arr=str2array.split(this.split);
//System.out.println("Array :"+arr.length);
return arr;
}
}
错误事例：
package myown;
import java.lang.reflect.Array;
import java.net.*;
import java.util.ArrayList;
import java.util.Arrays;
//import java.util.Set;
//import java.util.StringTokenizer;
//import java.util.concurrent.ForkJoinPool.ManagedBlocker;
import java.io.*;
public class urlgetcontent {
/**
* @param args
*/
public static void main(String[] args) {
//System.out.println(arr);
process process=new process();
process.setcode("sh600000");
process.Settime("2013-02-08");
System.out.println(process.gettime()); // the problem1
process.pracess();
}
}
class process
{
private String time;
private String code;
public void Settime(String time)
{
this.time=time;
}
public void setcode(String code)
{
this.code=code;
}
public String gettime()
{
return this.time;
}
public String getcode()
{
return this.code;
}
public void pracess() {
// TODO Auto-generated constructor stub
urlprocess processUrlprocess =new urlprocess();
processUrlprocess.ReArray("http://market.finance.sina.com.cn/downxls.php?date="+this.time+"&symbol="+this.code);
}
}
class urlprocess
{
public ArrayList<String> urlprocess(String url) throws Exception
{
URL oracle = new URL(url);
BufferedReader in = new BufferedReader(
new InputStreamReader(oracle.openStream()));
String inputLine;
ArrayList<String> man=new ArrayList<String>();
while ((inputLine = in.readLine()) != null)
{
man.add(inputLine);
}
man.remove(0);
return man;
}
// #pointer
public void ReArray(String url)
{
process process=new process();
StringToArray sta=new StringToArray("\t");
try {
System.out.println(process.gettime()); //the problem2
ArrayList<String> newurllist=urlprocess(url);
String[][] results=new String[newurllist.size()][];
for (int i = 0; i <newurllist.size(); i++) {
results[i]=sta.str2array((String)newurllist.get(i));
results[i]= Arrays.copyOf(results[i], results[i].length+2);
// System.out.println(process.getcode());
// results[i][results.length-2]=process.getcode();
//results[i][results.length-1]=process.gettime();
}
//System.out.println(Arrays.deepToString(results));
} catch (Exception e) {
// TODO: handle exception
}
}
}
class StringToArray {
private String split;
public StringToArray(String split)
{
this.split=split;
}
public String[] str2array(String s)
{
String str2array=s;
//1. First method with split()
// split(String Delimiter)
String[] arr=str2array.split(this.split);
//System.out.println("Array :"+arr.length);
return arr;
}
}
上面这段代码，我现在需要在类urlprocess中的ReArray方法中调用process类中的gettime方法，但是rearray方法输出后的结果是null，而我在main函数中调用该方法就可以正常输出，问题出现在什么地方，出问题的地方我使用 the problem 进行了注释，the problem1是在main函数中调用，the problem2是在rearray方法中调用，第一个可以正常输出，第二个输出为空，但是我现在需要在rearray方法中调用gettime方法，请问该怎么写
错误原因：在类中建立了对象，而调用的方法，没有传值