Java Parser.parse方法代码示例

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
/**
 * 动态反序列：通过Schema文件进行动态反序列化操作
 * 
 * @throws IOException
 */
public void MemberInfoDynDeser() throws IOException {
    // 1.schema文件解析
    Parser parser = new Parser();
    Schema mSchema = parser.parse(this.getClass().getResourceAsStream("/Members.avsc"));

    // 2.构建数据读对象
    DatumReader<GenericRecord> mGr = new SpecificDatumReader<GenericRecord>(mSchema);
    DataFileReader<GenericRecord> mDfr = new DataFileReader<GenericRecord>(new File("/Users/a/Desktop/tmp/members.avro"), mGr);
    // 3.从序列化文件中进行数据反序列化取出数据
    GenericRecord gr = null;
    while (mDfr.hasNext()) {
        gr = mDfr.next();
        System.err.println("deser data:" + gr.toString());
    }
    mDfr.close();
    System.out.println("Dyn Builder Ser Start Complete.");
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
/**
 * 动态序列化：通过动态解析Schema文件进行内容设置，并序列化内容
 * 
 * @throws IOException
 */
public void MemberInfoDynSer() throws IOException {
    // 1.解析schema文件内容
    Parser parser = new Parser();
    Schema mSchema = parser.parse(this.getClass().getResourceAsStream("/Members.avsc"));
    // 2.构建数据写对象
    DatumWriter<GenericRecord> mGr = new SpecificDatumWriter<GenericRecord>(mSchema);
    DataFileWriter<GenericRecord> mDfw = new DataFileWriter<GenericRecord>(mGr);
    // 3.创建序列化文件
    mDfw.create(mSchema, new File("/Users/a/Desktop/tmp/members.avro"));
    // 4.添加序列化数据
    for (int i = 0; i < 20; i++) {
        GenericRecord gr = new GenericData.Record(mSchema);
        int r = i * new Random().nextInt(50);
        gr.put("userName", "light-" + r);
        gr.put("userPwd", "2016-" + r);
        gr.put("realName", "滔滔" + r + "号");
        mDfw.append(gr);
    }
    // 5.关闭数据文件写对象
    mDfw.close();
    System.out.println("Dyn Builder Ser Start Complete.");
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
@Test
public void testGenerateAvro3() {
	try {
		Parser parser = new Schema.Parser();
		Schema peopleSchema = parser.parse(new File(getTestResource("people.avsc").toURI()));
		GenericDatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<GenericRecord>(peopleSchema);
		DataFileWriter<GenericRecord> dfw = new DataFileWriter<GenericRecord>(datumWriter);
		File tempfile = File.createTempFile("karma-people", "avro");
		
		tempfile.deleteOnExit();
		dfw.create(peopleSchema, new FileOutputStream(tempfile));
		JSONArray array = new JSONArray(IOUtils.toString(new FileInputStream(new File(getTestResource("people.json").toURI()))));
		for(int i = 0; i < array.length(); i++)
		{
			dfw.append(generatePersonRecord(peopleSchema, array.getJSONObject(i)));
		}
		dfw.flush();
		dfw.close();
	} catch (Exception e) {
		logger.error("testGenerateAvro3 failed:", e);
		fail("Execption: " + e.getMessage());
	}
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
public JsonReader(String dataFilepath, String schemaFilepath) throws Exception{
	this.filepath = dataFilepath;
	Parser parser = new Schema.Parser();
	Schema schema = parser.parse(new File(schemaFilepath));
	this.datumReader = new SpecificDatumReader<Object>(schema);
	this.decoder = DecoderFactory.get().jsonDecoder(schema, 
			new FileInputStream(new File(dataFilepath)));
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
public BinaryReader(String dataFilepath, String schemaFilepath) throws Exception{
	this.filepath = dataFilepath;
	Parser parser = new Schema.Parser();
	Schema schema = parser.parse(new File(schemaFilepath));
	DatumReader<Object> datumReader = new SpecificDatumReader<Object>(schema);
	this.dataFileReader = new DataFileReader<>(new File(dataFilepath), datumReader);
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
public FileWriter(String schemaFile, String outputFile) throws IOException{
	Parser parser = new Schema.Parser();
	Schema schema = parser.parse(new File(schemaFile));
       DatumWriter<Object> datumWriter = new SpecificDatumWriter<Object>(schema);
	fileWriter = new DataFileWriter<>(datumWriter);
	fileWriter.create(schema, new File(outputFile));
}
 

import org.apache.avro.Schema.Parser; //导入方法依赖的package包/类
public JsonFileWriter(String schemaFile, String outputFilePath) throws Exception{
	
	File outputFile = new File(outputFilePath);
	if(outputFile == null || outputFile.getParentFile() == null || !outputFile.getParentFile().exists()){
		throw new Exception("Invalid file path: " + outputFilePath);
	}
	
	Parser parser = new Schema.Parser();
	Schema schema = parser.parse(new File(schemaFile));
	datumWriter = new SpecificDatumWriter<Object>(schema);
	OutputStream outputStream = new FileOutputStream(outputFile);
	jsonEncoder = EncoderFactory.get().jsonEncoder(schema, outputStream);
}