xml文件解析和序列化

转载：http://blog.csdn.net/liuhe688/article/details/6415593

 XmlPullParser parser = Xml.newPullParser(); //由android.util.Xml创建一个XmlPullParser实例
        parser.setInput(is, "UTF-8");               //设置输入流 并指明编码方式

        int eventType = parser.getEventType();
        while (eventType != XmlPullParser.END_DOCUMENT) {
            switch (eventType) {
            case XmlPullParser.START_DOCUMENT:
                books = new ArrayList<Book>();
                break;
            case XmlPullParser.START_TAG:
                if (parser.getName().equals("book")) {
                    book = new Book();
                } else if (parser.getName().equals("id")) {
                    eventType = parser.next();
                    book.setId(Integer.parseInt(parser.getText()));
                } else if (parser.getName().equals("name")) {
                    eventType = parser.next();  　　            //parser.getAttributeName(0) 当前标签内第0个属性的名称   parser.getAttributeValue(0)  当前标签内第0个属性对应的值
　　                                                              //parser.getAttributeValue("","name"); 得到当前标签内名称为name的值，默认为“”
                    book.setName(parser.getText());
                } else if (parser.getName().equals("price")) {
                    eventType = parser.next();
                    book.setPrice(Float.parseFloat(parser.getText()));
                }
                break;
            case XmlPullParser.END_TAG:
                if (parser.getName().equals("book")) {
                    books.add(book);
                    book = null;
                }
                break;
            }
            eventType = parser.next();
        }
        return books;
    }

    @Override
    public String serialize(List<Book> books) throws Exception {
//      XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
//      XmlSerializer serializer = factory.newSerializer();

        XmlSerializer serializer = Xml.newSerializer(); //由android.util.Xml创建一个XmlSerializer实例
        StringWriter writer = new StringWriter();
        serializer.setOutput(writer);   //设置输出方向为writer
        serializer.startDocument("UTF-8", true);
        serializer.startTag("", "books");
        for (Book book : books) {
            serializer.startTag("", "book");
            serializer.attribute("", "id", book.getId() + "");

            serializer.startTag("", "name");
            serializer.text(book.getName());
            serializer.endTag("", "name");

            serializer.startTag("", "price");
            serializer.text(book.getPrice() + "");
            serializer.endTag("", "price");

            serializer.endTag("", "book");
        }
        serializer.endTag("", "books");
        serializer.endDocument();

        return writer.toString();
    }
}