如何从Java高效地将For循环中的（700000行）内容写入文件？

我编写了以下代码，以XML响应的形式获取结果，并将其部分内容从Java写入a文件。这是通过接收对一个公共数据库的大约700000个查询的XML响应来完成的

但是，在代码可以写入文件之前，它要么被代码中某个随机位置的某个随机异常（来自服务器）停止。我试图从For循环本身写入该文件，但无法完成。因此，我尝试将收到的响应中的块存储到Java HashMap中，并在一次调用中将HashMap写入文件。但是，在代码接收for循环中的所有响应并将它们存储到HashMap之前，它会因一些异常而停止（可能在第15000次迭代时！！）。当需要这样的迭代来获取数据时，有没有其他有效的方法在Java中写入文件

我用于此代码的本地文件是

我的密码是

import java.io.BufferedReader;              

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.XML;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;


public class random {

    static FileWriter fileWriter;
    static PrintWriter writer;

    public static void main(String[] args) {

        // Hashmap to store the MeSH values for each PMID 
        Map<String, String> universalMeSHMap = new HashMap<String, String>();

        try {

            // FileWriter for MeSH terms
            fileWriter = new FileWriter("/home/user/eclipse-workspace/pmidtomeshConverter/src/main/resources/outputFiles/pmidMESH.txt", true);
            writer = new PrintWriter(fileWriter);

            // Read the PMIDS from this file 
            String filePath = "file_attached_to_Post.txt";
            String line = null;
            BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath));


            String[] pmidsAll = null;

            int x = 0;
            try {
                //print first 2 lines or all if file has less than 2 lines
                while(((line = bufferedReader.readLine()) != null) && x < 1) {
                    pmidsAll = line.split(",");
                    x++;
                }   
            }
            finally {   
                bufferedReader.close();         
            }

            // List of strings containing the PMIDs
            List<String> pmidList = Arrays.asList(pmidsAll);

            // Iterate through the list of PMIDs to fetch the XML files from PubMed using eUtilities API service from PubMed
            for (int i = 0; i < pmidList.size(); i++) {


                String baseURL = "https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&retmode=xml&rettype=abstract&id=";

                // Process to get the PMIDs
                String indPMID_p0 = pmidList.get(i).toString().replace("[", "");
                String indPMID_p1 = indPMID_p0.replace("]", "");
                String indPMID_p2 = indPMID_p1.replace("\\", "");
                String indPMID_p3 = indPMID_p2.replace("\"", "");

                // Fetch XML response from the eUtilities into a document object 
                Document doc = parseXML(new URL(baseURL + indPMID_p3));

                // Convert the retrieved XMl into a Java String 
                String xmlString = xml2String(doc); // Converts xml from doc into a string

                // Convert the Java String into a JSON Object
                JSONObject jsonWithMeSH = XML.toJSONObject(xmlString);  // Converts the xml-string into JSON

                // -------------------------------------------------------------------
                // Getting the MeSH terms from a JSON Object
                // -------------------------------------------------------------------
                JSONObject ind_MeSH = jsonWithMeSH.getJSONObject("PubmedArticleSet").getJSONObject("PubmedArticle").getJSONObject("MedlineCitation");

                // List to store multiple MeSH types
                List<String> list_MeSH = new ArrayList<String>();
                if (ind_MeSH.has("MeshHeadingList")) {

                    for (int j = 0; j < ind_MeSH.getJSONObject("MeshHeadingList").getJSONArray("MeshHeading").length(); j++) {
                        list_MeSH.add(ind_MeSH.getJSONObject("MeshHeadingList").getJSONArray("MeshHeading").getJSONObject(j).getJSONObject("DescriptorName").get("content").toString());
                    }
                } else {

                    list_MeSH.add("null");

                }

                universalMeSHMap.put(indPMID_p3, String.join("\t", list_MeSH));

                writer.write(indPMID_p3 + ":" + String.join("\t", list_MeSH) + "\n");



            System.out.println("Completed iteration for " + i + " PMID");

        }

        // Write to the file here
        for (Map.Entry<String,String> entry : universalMeSHMap.entrySet()) {

            writer.append(entry.getKey() + ":" +  entry.getValue() + "\n");

        }

        System.out.print("Completed writing the file");

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ParserConfigurationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (SAXException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (TransformerException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        writer.flush();
        writer_pubtype.flush();
        writer.close();
        writer_pubtype.close();
    }

}

private static String xml2String(Document doc) throws TransformerException {

    TransformerFactory transfac = TransformerFactory.newInstance();
    Transformer trans = transfac.newTransformer();
    trans.setOutputProperty(OutputKeys.METHOD, "xml");
    trans.setOutputProperty(OutputKeys.INDENT, "yes");
    trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", Integer.toString(2));

    StringWriter sw = new StringWriter();
    StreamResult result = new StreamResult(sw);
    DOMSource source = new DOMSource(doc.getDocumentElement());

    trans.transform(source, result);
    String xmlString = sw.toString();
    return xmlString;

}

private static Document parseXML(URL url) throws ParserConfigurationException, SAXException, IOException {
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document doc = db.parse((url).openStream());
    doc.getDocumentElement().normalize();
    return doc;
}

private static String readAll(Reader rd) throws IOException {
    StringBuilder sb = new StringBuilder();
    int cp;
    while ((cp = rd.read()) != -1) {
        sb.append((char) cp);
    }
    return sb.toString();
}

public static JSONObject readJsonFromUrl(String url) throws IOException, JSONException {
    InputStream is = new URL(url).openStream();
    try {
        BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
        String jsonText = readAll(rd);
        JSONObject json = new JSONObject(jsonText);
        return json;
    } finally {
        is.close();
    }
}

导入java.io.BufferedReader；
导入java.io.FileNotFoundException；
导入java.io.FileReader；
导入java.io.FileWriter；
导入java.io.IOException；
导入java.io.InputStream；
导入java.io.InputStreamReader；
导入java.io.PrintWriter；
导入java.io.Reader；
导入java.io.StringWriter；
导入java.net.URL；
导入java.nio.charset.charset；
导入java.util.ArrayList；
导入java.util.array；
导入java.util.HashMap；
导入java.util.List；
导入java.util.Map；
导入javax.xml.parsers.DocumentBuilder；
导入javax.xml.parsers.DocumentBuilderFactory；
导入javax.xml.parsers.parserConfiguration异常；
导入javax.xml.transform.OutputKeys；
导入javax.xml.transform.Transformer；
导入javax.xml.transform.TransformerException；
导入javax.xml.transform.TransformerFactory；
导入javax.xml.transform.dom.DOMSource；
导入javax.xml.transform.stream.StreamResult；
导入org.json.JSONArray；
导入org.json.JSONException；
导入org.json.JSONObject；
导入org.json.XML；
导入org.w3c.dom.Document；
导入org.xml.sax.SAXException；
公共类随机{
静态文件编写器；
静态打印机；
公共静态void main（字符串[]args）{
//Hashmap存储每个PMID的网格值
Map universalMeSHMap=新HashMap（）；
试一试{
//网格术语的FileWriter
fileWriter=newfilewriter（“/home/user/eclipse workspace/pmidtomeshConverter/src/main/resources/outputFiles/pmidMESH.txt”，true）；
writer=新的PrintWriter（fileWriter）；
//从该文件中读取PMID
String filePath=“file\u attached\u to\u Post.txt”；
字符串行=null；
BufferedReader BufferedReader=新的BufferedReader（新文件读取器（文件路径））；
字符串[]pmidsAll=null；
int x=0；
试一试{
//打印前2行或全部（如果文件少于2行）
而（（line=bufferedReader.readLine（））！=null）和&x<1）{
pmidsAll=line.split（“，”）；
x++；
}   
}
最后{
bufferedReader.close（）；
}
//包含PMID的字符串列表
List pmidList=Arrays.asList（pmidsAll）；
//使用PubMed的eUtilities API服务，遍历PMID列表，从PubMed获取XML文件
对于（int i=0；idbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);

private static DocumentBuilderFactory dbf;

public static void main(String[] args) {
    dbf = DocumentBuilderFactory.newInstance();
    dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
    dbf.setFeature("http://xml.org/sax/features/validation", false);
    ...
}

private static Document parseXML(URL url) throws ParserConfigurationException, SAXException, IOException {
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document doc = db.parse((url).openStream());
    doc.getDocumentElement().normalize();
    return doc;
}