OutOfMemoryError异常：Java堆空间，如何调试。。。？
我得到一个java.lang.OutOfMemoryError异常：java堆空间 我正在解析一个XML文件，存储数据并在解析完成后输出一个XML文件 我对出现这样的错误感到有点惊讶，因为原始XML文件根本不长 代码： 文件：可以尝试将Eclipse.ini文件中的-Xms和-Xmx值设置得更高 ex） -vmargs -Xms128m/（初始堆大小）OutOfMemoryError异常：Java堆空间，如何调试。。。？,java,debugging,memory,memory-leaks,profiler,Java,Debugging,Memory,Memory Leaks,Profiler,我得到一个java.lang.OutOfMemoryError异常：java堆空间 我正在解析一个XML文件，存储数据并在解析完成后输出一个XML文件 我对出现这样的错误感到有点惊讶，因为原始XML文件根本不长 代码： 文件：可以尝试将Eclipse.ini文件中的-Xms和-Xmx值设置得更高 ex） -vmargs -Xms128m/（初始堆大小） -Xmx256m/（最大堆大小）如果这是您只想完成的一次性任务，我会尝试Jason关于增加Java可用内存的建议 您正在构建一个非常大的对象列表
-Xmx256m/（最大堆大小）如果这是您只想完成的一次性任务，我会尝试Jason关于增加Java可用内存的建议
您正在构建一个非常大的对象列表，然后在该列表中循环以输出字符串，然后将该字符串写入文件。列表和字符串可能是内存使用率高的原因。您可以以更面向流的方式重新组织代码。首先打开文件输出，然后在解析每个质心时为其编写XML。这样，您就不需要保存它们的大列表，也不需要保存表示所有XML的大字符串。转储堆并分析它。您可以使用
-XX:+HeapDumpOnOutOfMemoryError第四，你是如何使用这些数据的。您正在处理一个文件还是多个文件？您是否在解析后意外地保留了数据？代码示例在这里会有所帮助（而指向某个第三方网站的链接对于未来的SO用户来说并不是非常有用）。好的，我承认我正在用一个可能的替代方案来避免您的直接问题。您可能想考虑解析，而不是用更少的代码来处理大部分的工作。下面我的粗略示例使用64MB堆解析XML。请注意，它还需要ApacheCommonsIO来轻松读取输入，以便黑客将
导入java.io.File；
导入java.io.IOException；
导入java.util.List；
导入org.apache.commons.io.FileUtils；
导入com.thoughtworks.xstream.xstream；
导入com.thoughtworks.xstream.annotations.XStreamAlias；
公共类质心发生器{
公共静态void main（字符串[]args）引发IOException{
for（Centroid-Centroid:getCentroids（新文件（“PjrE.data.xml”））{
System.out.println（centroid.title+“-”+centroid.description）；
}
}
@抑制警告（“未选中”）
公共静态列表getCentroids（文件）引发IOException{
字符串输入=FileUtils.readFileToString（文件，“UTF-8”）；
input=input.replaceAll（“集合>”，“列表>”）；
XStream XStream=新的XStream（）；
processAnnotations（Centroid.class）；
对象输出=xstream.fromXML（输入）；
返回（列表）输出；
}
@XStreamAlias（“文件”）
@抑制警告（“未使用”）
公共静态类质心{
私有字符串id；
私有字符串标题；
私有字符串描述；
私有字符串时间；
私有字符串标签；
私有字符串纬度；
私有字符串经度；
私有字符串事件；
私人字符串；
}
}
也许你应该阅读--实际上阅读我以前的帖子，并用它要求的信息更新你的问题。或者，如果您不愿意这么做，请接受您的F.简短回答，解释为什么会出现OutOfMemoryError，对于文件中找到的每个质心，您将循环检查已经“注册”的质心，以检查它是否已知（添加新质心或更新已经注册的质心）。但对于每次失败的比较，您都会添加新质心的新副本。因此，对于每个新的质心，它添加它的次数与列表中已有的质心相同，然后你遇到你添加的第一个质心，你更新它，然后离开循环 以下是一些重构代码：
public class CentroidGenerator {
final Map<String, Centroid> centroids = new HashMap<String, Centroid>();
public Collection<Centroid> getCentroids() {
return centroids.values();
}
public void nextItem(FlickrDoc flickrDoc) {
final String event = flickrDoc.getEvent();
final Centroid existingCentroid = centroids.get(event);
if (existingCentroid != null) {
existingCentroid.update(flickrDoc);
} else {
final Centroid newCentroid = new Centroid(flickrDoc);
centroids.put(event, newCentroid);
}
}
public static void main(String[] args) throws IOException, SAXException {
// instantiate Digester and disable XML validation
[...]
// now that rules and actions are configured, start the parsing process
CentroidGenerator abp = (CentroidGenerator) digester.parse(new File("PjrE.data.xml"));
Writer writer = null;
try {
File fileOutput = new File("centroids.xml");
writer = new BufferedWriter(new FileWriter(fileOutput));
writeOuput(writer, abp.getCentroids());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void writeOuput(Writer writer, Collection<Centroid> centroids) throws IOException {
writer.append("<?xml version='1.0' encoding='utf-8'?>" + System.getProperty("line.separator"));
writer.append("<collection>").append(System.getProperty("line.separator"));
for (Centroid centroid : centroids) {
writer.append("<doc>" + System.getProperty("line.separator"));
writer.append("<title>" + System.getProperty("line.separator"));
writer.append(centroid.getTitle());
writer.append("</title>" + System.getProperty("line.separator"));
writer.append("<description>" + System.getProperty("line.separator"));
writer.append(centroid.getDescription());
writer.append("</description>" + System.getProperty("line.separator"));
writer.append("<time>" + System.getProperty("line.separator"));
writer.append(centroid.getTime());
writer.append("</time>" + System.getProperty("line.separator"));
writer.append("<tags>" + System.getProperty("line.separator"));
writer.append(centroid.getTags());
writer.append("</tags>" + System.getProperty("line.separator"));
writer.append("<geo>" + System.getProperty("line.separator"));
writer.append("<lat>" + System.getProperty("line.separator"));
writer.append(centroid.getLat());
writer.append("</lat>" + System.getProperty("line.separator"));
writer.append("<lng>" + System.getProperty("line.separator"));
writer.append(centroid.getLng());
writer.append("</lng>" + System.getProperty("line.separator"));
writer.append("</geo>" + System.getProperty("line.separator"));
writer.append("</doc>" + System.getProperty("line.separator"));
}
writer.append("</collection>" + System.getProperty("line.separator") + System.getProperty("line.separator"));
}
/**
* JavaBean class that holds properties of each Document entry. It is important that this class be public and
* static, in order for Digester to be able to instantiate it.
*/
public static class FlickrDoc {
private String id;
private String title;
private String description;
private String time;
private String tags;
private String latitude;
private String longitude;
private String event;
public void setId(String newId) {
id = newId;
}
public String getId() {
return id;
}
public void setTitle(String newTitle) {
title = newTitle;
}
public String getTitle() {
return title;
}
public void setDescription(String newDescription) {
description = newDescription;
}
public String getDescription() {
return description;
}
public void setTime(String newTime) {
time = newTime;
}
public String getTime() {
return time;
}
public void setTags(String newTags) {
tags = newTags;
}
public String getTags() {
return tags;
}
public void setLatitude(String newLatitude) {
latitude = newLatitude;
}
public String getLatitude() {
return latitude;
}
public void setLongitude(String newLongitude) {
longitude = newLongitude;
}
public String getLongitude() {
return longitude;
}
public void setEvent(String newEvent) {
event = newEvent;
}
public String getEvent() {
return event;
}
}
public static class Centroid {
private final String event;
private String title;
private String description;
private String tags;
private Integer time;
private int nbTimeValues = 0; // needed to calculate the average later
private Float latitude;
private int nbLatitudeValues = 0; // needed to calculate the average later
private Float longitude;
private int nbLongitudeValues = 0; // needed to calculate the average later
public Centroid(FlickrDoc flickrDoc) {
event = flickrDoc.event;
title = flickrDoc.title;
description = flickrDoc.description;
tags = flickrDoc.tags;
if (flickrDoc.time != null) {
time = Integer.valueOf(flickrDoc.time.trim());
nbTimeValues = 1; // time is the sum of one value
}
if (flickrDoc.latitude != null) {
latitude = Float.valueOf(flickrDoc.latitude.trim());
nbLatitudeValues = 1; // latitude is the sum of one value
}
if (flickrDoc.longitude != null) {
longitude = Float.valueOf(flickrDoc.longitude.trim());
nbLongitudeValues = 1; // longitude is the sum of one value
}
}
public void update(FlickrDoc newData) {
title = title + " " + newData.title;
description = description + " " + newData.description;
tags = tags + " " + newData.tags;
if (newData.time != null) {
nbTimeValues++;
if (time == null) {
time = 0;
}
time += Integer.valueOf(newData.time.trim());
}
if (newData.latitude != null) {
nbLatitudeValues++;
if (latitude == null) {
latitude = 0F;
}
latitude += Float.valueOf(newData.latitude.trim());
}
if (newData.longitude != null) {
nbLongitudeValues++;
if (longitude == null) {
longitude = 0F;
}
longitude += Float.valueOf(newData.longitude.trim());
}
}
public String getTitle() {
return title;
}
public String getDescription() {
return description;
}
public String getTime() {
if (nbTimeValues == 0) {
return null;
} else {
return Integer.toString(time / nbTimeValues);
}
}
public String getTags() {
return tags;
}
public String getLat() {
if (nbLatitudeValues == 0) {
return null;
} else {
return Float.toString(latitude / nbLatitudeValues);
}
}
public String getLng() {
if (nbLongitudeValues == 0) {
return null;
} else {
return Float.toString(longitude / nbLongitudeValues);
}
}
public String getEvent() {
return event;
}
}
}
公共类质心生成器{
最终贴图质心=新HashMap（）；
公共集合getCentroids（）{
返回质心值（）；
}
public void nextItem（FlickrDoc FlickrDoc）{
最后一个字符串event=flickrDoc.getEvent（）；
最终质心existingCentroid=质心.get（事件）；
if（existingCentroid！=null）{
现有形心更新（flickrDoc）；
}否则{
最终质心newCentroid=新质心（flickrDoc）；
质心。放置（事件，新质心）；
}
}
公共静态void main（字符串[]args）引发IOException、SAXException{
//实例化摘要并禁用XML验证
[...]
//既然规则和行动
public class CentroidGenerator {
final Map<String, Centroid> centroids = new HashMap<String, Centroid>();
public Collection<Centroid> getCentroids() {
return centroids.values();
}
public void nextItem(FlickrDoc flickrDoc) {
final String event = flickrDoc.getEvent();
final Centroid existingCentroid = centroids.get(event);
if (existingCentroid != null) {
existingCentroid.update(flickrDoc);
} else {
final Centroid newCentroid = new Centroid(flickrDoc);
centroids.put(event, newCentroid);
}
}
public static void main(String[] args) throws IOException, SAXException {
// instantiate Digester and disable XML validation
[...]
// now that rules and actions are configured, start the parsing process
CentroidGenerator abp = (CentroidGenerator) digester.parse(new File("PjrE.data.xml"));
Writer writer = null;
try {
File fileOutput = new File("centroids.xml");
writer = new BufferedWriter(new FileWriter(fileOutput));
writeOuput(writer, abp.getCentroids());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void writeOuput(Writer writer, Collection<Centroid> centroids) throws IOException {
writer.append("<?xml version='1.0' encoding='utf-8'?>" + System.getProperty("line.separator"));
writer.append("<collection>").append(System.getProperty("line.separator"));
for (Centroid centroid : centroids) {
writer.append("<doc>" + System.getProperty("line.separator"));
writer.append("<title>" + System.getProperty("line.separator"));
writer.append(centroid.getTitle());
writer.append("</title>" + System.getProperty("line.separator"));
writer.append("<description>" + System.getProperty("line.separator"));
writer.append(centroid.getDescription());
writer.append("</description>" + System.getProperty("line.separator"));
writer.append("<time>" + System.getProperty("line.separator"));
writer.append(centroid.getTime());
writer.append("</time>" + System.getProperty("line.separator"));
writer.append("<tags>" + System.getProperty("line.separator"));
writer.append(centroid.getTags());
writer.append("</tags>" + System.getProperty("line.separator"));
writer.append("<geo>" + System.getProperty("line.separator"));
writer.append("<lat>" + System.getProperty("line.separator"));
writer.append(centroid.getLat());
writer.append("</lat>" + System.getProperty("line.separator"));
writer.append("<lng>" + System.getProperty("line.separator"));
writer.append(centroid.getLng());
writer.append("</lng>" + System.getProperty("line.separator"));
writer.append("</geo>" + System.getProperty("line.separator"));
writer.append("</doc>" + System.getProperty("line.separator"));
}
writer.append("</collection>" + System.getProperty("line.separator") + System.getProperty("line.separator"));
}
/**
* JavaBean class that holds properties of each Document entry. It is important that this class be public and
* static, in order for Digester to be able to instantiate it.
*/
public static class FlickrDoc {
private String id;
private String title;
private String description;
private String time;
private String tags;
private String latitude;
private String longitude;
private String event;
public void setId(String newId) {
id = newId;
}
public String getId() {
return id;
}
public void setTitle(String newTitle) {
title = newTitle;
}
public String getTitle() {
return title;
}
public void setDescription(String newDescription) {
description = newDescription;
}
public String getDescription() {
return description;
}
public void setTime(String newTime) {
time = newTime;
}
public String getTime() {
return time;
}
public void setTags(String newTags) {
tags = newTags;
}
public String getTags() {
return tags;
}
public void setLatitude(String newLatitude) {
latitude = newLatitude;
}
public String getLatitude() {
return latitude;
}
public void setLongitude(String newLongitude) {
longitude = newLongitude;
}
public String getLongitude() {
return longitude;
}
public void setEvent(String newEvent) {
event = newEvent;
}
public String getEvent() {
return event;
}
}
public static class Centroid {
private final String event;
private String title;
private String description;
private String tags;
private Integer time;
private int nbTimeValues = 0; // needed to calculate the average later
private Float latitude;
private int nbLatitudeValues = 0; // needed to calculate the average later
private Float longitude;
private int nbLongitudeValues = 0; // needed to calculate the average later
public Centroid(FlickrDoc flickrDoc) {
event = flickrDoc.event;
title = flickrDoc.title;
description = flickrDoc.description;
tags = flickrDoc.tags;
if (flickrDoc.time != null) {
time = Integer.valueOf(flickrDoc.time.trim());
nbTimeValues = 1; // time is the sum of one value
}
if (flickrDoc.latitude != null) {
latitude = Float.valueOf(flickrDoc.latitude.trim());
nbLatitudeValues = 1; // latitude is the sum of one value
}
if (flickrDoc.longitude != null) {
longitude = Float.valueOf(flickrDoc.longitude.trim());
nbLongitudeValues = 1; // longitude is the sum of one value
}
}
public void update(FlickrDoc newData) {
title = title + " " + newData.title;
description = description + " " + newData.description;
tags = tags + " " + newData.tags;
if (newData.time != null) {
nbTimeValues++;
if (time == null) {
time = 0;
}
time += Integer.valueOf(newData.time.trim());
}
if (newData.latitude != null) {
nbLatitudeValues++;
if (latitude == null) {
latitude = 0F;
}
latitude += Float.valueOf(newData.latitude.trim());
}
if (newData.longitude != null) {
nbLongitudeValues++;
if (longitude == null) {
longitude = 0F;
}
longitude += Float.valueOf(newData.longitude.trim());
}
}
public String getTitle() {
return title;
}
public String getDescription() {
return description;
}
public String getTime() {
if (nbTimeValues == 0) {
return null;
} else {
return Integer.toString(time / nbTimeValues);
}
}
public String getTags() {
return tags;
}
public String getLat() {
if (nbLatitudeValues == 0) {
return null;
} else {
return Float.toString(latitude / nbLatitudeValues);
}
}
public String getLng() {
if (nbLongitudeValues == 0) {
return null;
} else {
return Float.toString(longitude / nbLongitudeValues);
}
}
public String getEvent() {
return event;
}
}
}