我有一个arrayLists的树状图。我需要检查每个列表中的匹配元素。我的代码可以正常工作，只不过它仅针对数组<=本身检查数组。其他阵列运行良好。我以为这是我所缺少的愚蠢错误，但是..
ArrayList<Integer> currentArray;
ArrayList<Integer> compareArray;
//Setting user friend list
//cycle users "i"
for(int i = 1; i <= treemap.size(); i++){
currentArray = treemap.get(i);
//cycle user "k"
for(int k=1; k <= treemap.size(); k++){
//if(i!=k){ Put back in once working
compareArray = treemap.get(k);
//cylce "k"s movie list
for(int l=0; l < compareArray.size(); l++){
if(currentArray.contains(compareArray.get(l))){
if (treemap2.containsKey(i)){
ArrayList<Integer> list3 = treemap2.get(i);
list3.add(k);
treemap2.remove(i);
treemap2.put(i, list3);
}
if (!treemap2.containsKey(i)){
ArrayList<Integer> list4 = new ArrayList<Integer>();
list4.add(k);
treemap2.put(i, list4);
}
}
}
}
}
//Create string of friends
for(ArrayList<Integer> x: treemap2.values()){
str2 = Integer.toString(x.get(0));
for (int i = 1; i < x.size(); i++)
{
str2 = str2 + "," + Integer.toString(x.get(i)) ;
}
}
context.write(key, new Text(str2));
我仍然需要更正密钥，这很容易，并且不会以任何一种方式在最终程序中使用。
我应该得到 1 1,1,1,2,2 2 1,1,2,2,2 3 2,3,3,3
相反，我得到了 1 1,1,1 2 1,1,2,2,2 3 2,3,3,3
无论哪种方式，请先谢谢。 附带说明，执行以下操作即可获得所需的确切信息……除了它省去了最后一个数组。
//cycle current array "i"
for(int i = 1; i < treemap.size(); i++){
currentArray = treemap.get(i);
//cycle compare array "k"
for(int k=1; k <= treemap.size(); k++){
if(i!=k){ //
compareArray = treemap.get(k);
//cylce array element in compare "l"
for(int l=0; l < compareArray.size(); l++){
if(currentArray.contains(compareArray.get(l))){
if (treemap2.containsKey(i)){
ArrayList<String> list3 = treemap2.get(i);
list3.add(k+":"+compareArray.get(l));
treemap2.remove(i);
treemap2.put(i, list3);
}
if (!treemap2.containsKey(i)){
ArrayList<String> list4 = new ArrayList<String>();
list4.add(k+":"+compareArray.get(l));
treemap2.put(i, list4);
}
}
}
}
}
}
1 2105
1 1953
1 1339
2 2105
2 1321
2 1339
3 1321
3 1544
3 1222
答案 0 :(得分：2)
我对您的某些变量和数据定义有些不确定，因为这两个发布之间存在一些差异。但是，我创建了一个独立的Java程序，该程序隔离您的算法并使用模拟数据对其进行测试。整个程序都在下面，很小。
这是我使用跟踪和调试器断点的组合的通用方法，以便能够查看结果并检查关键点上的所有变量。
您可以纠正我对数据类型所做的任何错误假设。
我希望这会有所帮助。
package com.example.hadoop;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.TreeMap;
/**
* I took your original code posting (which differs somewhat from the second
* snippet) and I converted it into a stand alone Java program with mock test
* data.
*
* This program would be my starting point to finding the logic error.
*
* My approach was to (1) isolate your algorithm, (2) mock out a minimal set of
* input data to test just the algorithm, and (3) step through with the debugger
* and/or use some trace statements.
*
* I made assumptions about variable definitions based on the code and
* information provided since I could not see all the actual definitions.
*
* Some of your data types differ between your two code fragments so I was a bit
* unsure about that.
*
* I may be wrong on some of the variable definitions so modify these as needed.
*
* You mentioned that:
*
* Expected result: 1 1,1,1,2,2 2 1,1,2,2,2 3 2,3,3,3
*
* Actual result: 1 1,1,1 2 1,1,2,2,2 3 2,3,3,3
*
* Massively truncated test data: 1 2105 1 1953 1 1339 2 2105 2 1321 2 1339 3
* 1321 3 1544 3 1222
*/
public class HadoopTestApp {
/*
* Mock test variables.
*/
ArrayList<Integer> datalist1 = new ArrayList<Integer>(Arrays.asList(2105, 1953, 1339));
ArrayList<Integer> datalist2 = new ArrayList<Integer>(Arrays.asList(2105, 1321, 1339));
ArrayList<Integer> datalist3 = new ArrayList<Integer>(Arrays.asList(1321, 1544, 1222));
TreeMap<Integer, ArrayList<Integer>> treemap = new TreeMap<Integer, ArrayList<Integer>>();
TreeMap<Integer, ArrayList<Integer>> treemap2 = new TreeMap<Integer, ArrayList<Integer>>();
String str2 = "";
/**
* Use the default constructor to complete the initialization of mock test
* variables.
*/
public HadoopTestApp() {
treemap.put(1, datalist1);
treemap.put(2, datalist2);
treemap.put(3, datalist3);
}
/**
* Bootstrap the test.
*
* @param args Command line arguments are not currently used.
*/
public static void main(String[] args) {
new HadoopTestApp().run(args);
}
/**
* If you prefer to trace variables manually. Or you can set some breakpoints
* and inspect variables in the debugger.
*/
public void doTrace(String label, Object o) {
System.out.print(label + ": ");
System.out.println(o);
}
/**
* Run the test of Hooch's algorithm.
*
* @param args Command line arguments are not currently used.
*/
public void run(String[] args) {
doTrace("treemap", treemap); // NEW
ArrayList<Integer> currentArray;
ArrayList<Integer> compareArray;
// Setting user friend list
// cycle users "i"
for (int i = 1; i <= treemap.size(); i++) {
currentArray = treemap.get(i);
// cycle user "k"
for (int k = 1; k <= treemap.size(); k++) {
// if(i!=k){ Put back in once working
compareArray = treemap.get(k);
// cylce "k"s movie list
for (int l = 0; l < compareArray.size(); l++) {
if (currentArray.contains(compareArray.get(l))) {
// NEW I set a debugger breakpoint on this line to inspect all variables
if (treemap2.containsKey(i)) {
ArrayList<Integer> list3 = treemap2.get(i);
list3.add(k);
treemap2.remove(i);
treemap2.put(i, list3);
doTrace("contains key, treemap2", treemap2); // NEW
}
if (!treemap2.containsKey(i)) {
ArrayList<Integer> list4 = new ArrayList<Integer>();
list4.add(k);
treemap2.put(i, list4);
doTrace("does not contain key, treemap2", treemap2); // NEW
}
}
}
}
}
// Create string of friends
for (ArrayList<Integer> x : treemap2.values()) {
str2 = Integer.toString(x.get(0));
for (int i = 1; i < x.size(); i++) {
str2 = str2 + "," + Integer.toString(x.get(i));
}
doTrace("in loop str2", str2); // NEW
}
// context.write(key, new Text(str2));
doTrace("context.write str2", str2); // NEW
}
}