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我正在使用 sax 解析器来解析 3.8 mb 的 xml 文件。解析时的加载时间几乎是 3.5 分钟。

public class sentmsghandler extends DefaultHandler {
public folder folderobj;
public Contact contact;
public Parent parent;
public Student student;
private StringBuilder builder;
Boolean repeat;

public folder getfolder() {
    return folderobj;
}

@Override
public void endElement(String uri, String localName, String qName)
        throws SAXException {
    // TODO Auto-generated method stub
    super.endElement(uri, localName, qName);
    // Log.i("testing parent contact",localName);
    if (this.folderobj != null) {

        String st = builder.toString();
        if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.SchoolName.toUpperCase())) {
            folderobj.setSchoolName(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.ParentCode.toUpperCase())) {
            parent.setParentCode(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.FamilyCode.toUpperCase())) {
            if (!repeat) {
                parent.setFamilyCode(st);
            } else {
                student.setFamilyCode(st);
            }
        }

        else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.FamilyName.toUpperCase())) {

            if (!repeat) {
                parent.setFamilyName(st);
            } else {
                student.setFamilyName(st);
            }
        }

        else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.GivenNames.toUpperCase())) {

            if (!repeat) {
                parent.setGivenNames(st);
            } else {
                student.setGivenNames(st);
            }
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.ParentType.toUpperCase())) {
            parent.setParentType(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.EmailAddress.toUpperCase())) {
            parent.setEmailAddress(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.MobilePhone.toUpperCase())) {
            parent.setMobilePhone(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.LandLineNumber.toUpperCase())) {
            parent.setLandLineNumber(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.Primary.toUpperCase())) {
            parent.setPrimary(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.StudentCode.toUpperCase())) {
            student.setStudentCode(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.SchoolYearLevel.toUpperCase())) {
            student.setSchoolYearLevel(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.RollClass.toUpperCase())) {
            student.setRollClass(st);
        } else if (localName.toUpperCase().equalsIgnoreCase(
                BaseFeedParser.House.toUpperCase())) {
            student.setHouse(st);
        }

    }
    builder.setLength(0);
}

@Override
public void startElement(String uri, String localName, String qName,
        Attributes attributes) throws SAXException {
    // TODO Auto-generated method stub
    super.startElement(uri, localName, qName, attributes);

    if (localName.toUpperCase().equalsIgnoreCase(
            BaseFeedParser.Folder.toUpperCase())) {
        folderobj = new folder();
    }

    else if (localName.toUpperCase().equalsIgnoreCase(
            BaseFeedParser.Contact.toUpperCase())) {
        contact = new Contact();
        folderobj.getContact_list().add(contact);
    } else if (localName.toUpperCase().equalsIgnoreCase(
            BaseFeedParser.Parent.toUpperCase())) {
        parent = new Parent();
        repeat = false;
        contact.getParent_list().add(parent);
    } else if (localName.toUpperCase().equalsIgnoreCase(
            BaseFeedParser.Student.toUpperCase())) {
        student = new Student();
        repeat = true;
        parent.getStudent_list().add(student);
    }

}

@Override
public void characters(char[] ch, int start, int length)
        throws SAXException {
    // TODO Auto-generated method stub
    super.characters(ch, start, length);
    builder.append(ch, start, length);
}

@Override
public void startDocument() throws SAXException {
    // TODO Auto-generated method stub
    super.startDocument();
    folderobj = new folder();
    builder = new StringBuilder();
    repeat = false;
}

}

Saxfeedparser.java

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class SaxFeedParser extends BaseFeedParser {

    public SaxFeedParser(String feedUrl) {
        super(feedUrl);
        // TODO Auto-generated constructor stub
    }

    public folder parse() throws RuntimeException {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        sentmsghandler handler = null;
        try {
            SAXParser parser = factory.newSAXParser();
            handler = new sentmsghandler();
            parser.parse(this.getInputStream(), handler);

        } catch (Exception e) {
            return null;
        }
        return handler.getfolder();
    }

}

Basefeedparser.java

public abstract class BaseFeedParser implements SentParser {

    // names of the XML tags
    static final String Folder = "Folder";
    static final String SchoolName = "SchoolName";
    static final String Contact = "Contact";
    static final String Parent = "Parent";
    static final String ParentCode = "ParentCode";
    static final String FamilyCode = "FamilyCode";
    static final String FamilyName = "FamilyName";
    static final String GivenNames = "GivenNames";
    static final String ParentType = "ParentType";
    static final String EmailAddress = "EmailAddress";
    static final String MobilePhone = "MobilePhone";
    static final String LandLineNumber = "LandLineNumber";
    static final String Primary = "Primary";
    static final String Student = "Student";
    static final String StudentCode = "StudentCode";
    static final String SchoolYearLevel = "SchoolYearLevel";
    static final String RollClass = "RollClass";
    static final String House = "House";

    //

    final URL feedUrl;

    protected BaseFeedParser(String feedUrl) {
        try {
            this.feedUrl = new URL(feedUrl);
        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }

    protected InputStream getInputStream() {
        try {
            return feedUrl.openConnection().getInputStream();
        } catch (IOException e) {
            return null;
        }
    }
}

在活动中调用代码

SaxFeedParser sax = new SaxFeedParser("link");// /check parents.xml
folder result = sax.parse();
4

1 回答 1

0

您可以改进的一件事：

而不是做

localName.toUpperCase().equalsIgnoreCase(
            BaseFeedParser.Contact.toUpperCase()

一直保存BaseFeedParser.Contact为大写，localName只转换一次为大写

localName = localName.toUpperCase();
if (localName.equals(BaseFeedParser.Folder)) {
    // something
} else if (localName.equals(BaseFeedParser.Contact)) {
   // something else
} else if (localName.equals(BaseFeedParser.Parent)) {
  // something here
}

这应该会给你一点速度提升。

如果您知道大小写不会改变，您甚至可以完全省略大写字母。

另一种可能加快字符串比较的技术是使用 HashMap

private static final int CASE_FOLDER = 1;
private static final int CASE_SCHOOLNAME = 2;
private static final HashMap<String, Integer> MAP = new HashMap<String, Integer>();
static {
    MAP.put("FOLDER", CASE_FOLDER);
    MAP.put("SCHOOLNAME", CASE_SCHOOLNAME);
}

然后做

localName = localName.toUpperCase();
int match = MAP.get(localName);
switch (match) {
    case CASE_FOLDER:
        // do something
        break;
 // etc
}
于 2012-04-24T10:23:24.840 回答