I am converting properties file into xml format like below .
public class XmlPropertiesWriter {
public static void main(String args[]) throws FileNotFoundException, IOException {
//Reading properties files in Java example
Properties props = new Properties();
FileOutputStream fos = new FileOutputStream("C:\\Users\\Desktop\\myxml.xml");
props.setProperty("key1", "test");
props.setProperty("key2", "test1");
//writing properites into properties file from Java
props.storeToXML(fos, "Properties file in xml format generated from Java program");
fos.close();
}
}
This is working fine.But I want to add one ArrayList into this xml file,How can I do this,Any one help me.
You can (un)serialized the list into string representation to store the data into the properties file:
ArrayList<String> list = new ArrayList<>( );
String serialized = list.stream( ).collect( Collectors.joining( "," ) );
String input = "data,data"
List<String> unserialized = Arrays.asList( input.split( "," ) );
With this method, take care to use a seperator which is never contained in your data.
Otherwise, write a xml (or json) file reader/writer to do what you want with support of list element
Depends on what type the ArrayList is. If it's a String type you can do
arrayList.toArray(new String[arrayList.size()]);
If the type is an object you can create a StringBuilder and add all the values seperated by a ; or : so you can split when needed
final StringBuilder builder = new Stringbuilder();
final List<Point> list = new ArrayList<Point>();
list.add(new Point(0, 0));
list.add(new Point(1, 0));
for(final Point p : list) {
builder.append(p.toString()).append(";");
}
properties.setProperty("list", builder.toString());
When you load the properties you can simply do then
final List<Point> list = new ArrayList<Point>();
final String[] points = properties.getProperty("list").split(";");
for(final String p : points) {
final int x = Integer.parseInt(p.substring(0, p.indexOf(","));
final int y = Integer.parseInt(p.substring(p.indexOf(","), p.indexOf(")"));
list.add(new Point(x, y);
}
Related
I am working on an reinforcement-learning project and have a List<INDArray> which holds a list of states of the world and a second List<INDArray>which holds action-prediction and reward values with the index corresponding to the states of the first List
I want to store these data for later training on the hard-drive, how can I achieve this?
Lets sax for example we have:
List<INDArray> stateList = new ArrayList<>();
stateList.add(Nd4j.valueArrayOf(new int[]{3,3,3}, 5));
stateList.add(Nd4j.valueArrayOf(new int[]{3,3,3}, 6));
List<INDArray> valueList = new ArrayList<>();
valueList.add(Nd4j.create(new float[]{1, 2}));
valueList.add(Nd4j.create(new float[]{3, 4}));
you have to preparefile content and then simply write into file.
String fileContent = "";
for (INDArray arr : valueList) {
str +=arr.getValue()+"/n";//arr.getValue() anything which u want to add
}
FileWriter fileWriter = new FileWriter("c:/temp/samplefile.txt");
fileWriter.write(fileContent);
fileWriter.close();
i'm trying to make a function
reading from specific directory and make a json file with that file's title in directory.
it reads file's title well but when i print out, it overlaps again and again
i need same key name and different value.
is there any way to put a number on key name or make same key?
bullet01.png
{"file":"bullet01.png"}
bullet011.png
{"file":"bullet011.png"}
bullet012.png
{"file":"bullet012.png"}
bullet013.png
{"file":"bullet013.png"}
bullet02.png
{"file":"bullet02.png"}
this is a full code
public void downloadFile(ViewMeta view) throws IOException {
DataSet input = view.getInputDataSet();
HttpServletRequest request = view.getHttpServletRequest();
String filePath = request.getServletContext().getRealPath("/curriculum1.4/filedir");
DataSet output = new DataSet();
File dir = new File(filePath);
String files[] = dir.list();
JSONObject data= new JSONObject();
for(String fn : files) {
System.out.println(fn);
data.put("file", fn);
System.out.println(data);
}
view.setAttribute("file", data);
view.printJSON();
}
this is a setAttribute structure
public void setAttribute(String key, Object val) {
if (this.keyList == null) {
this.keyList = new ArrayList();
}
this.keyList.add(key);
this.request.setAttribute(key, val);
this.request.setAttribute("coreframe.object.keyList", this.keyList);
}
if you want same key and have different value, you can make it as JSONArray format.
[{"file" : "bullet01.png"}, {"file" : "bullet02.png"}, {"file" : "bullet03.png"}]
your code may need to change like this :
.....
JSONArray array = new JSONArray();
for(String fn : files) {
//create json object for each file
JSONObject data= new JSONObject();
System.out.println(fn);
data.put("file", fn);
System.out.println(data);
//put json object into json array
array.put(data);
}
view.setAttribute("file", array);
view.printJSON();
No, the keys in the JSON should be unique. You can try appending numbers at the end of the key "file"
I am using msgpack to serialize data. I have some code works fine with serializing data.
public void testJackson() throws Exception {
ByteArrayOutputStream out = new ByteArrayOutputStream();
String data1 = "test data";
int data2 = 10;
List<String> data3 = new ArrayList<String>();
data3.add("list data1");
data3.add("list data1");
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(out, data1);
mapper.writeValue(out, data2);
mapper.writeValue(out, data3);
// TODO: How to deserialize?
}
But now I don't know how to deserialize data.
I am not finding any solution anywhere. It will be good if anyone can help how to proceed.
The problem
I have tried many of the readValue methods, but I only can get the first String, about the second and third value I have no idea
The thing is, Jackson always reads the first data, since the data is neither deleted from the nor did you explicitly tell Jackson that the next data is from position A to position B
Solutions
this example works and is similar to your code, but is not very elegant. Here I explicitly tell Jackson where my data is, but I have to know how it got written, which is a way too specific solution
File dataFile = new File("jackson.txt");
if(!dataFile.exists())
dataFile.createNewFile();
FileOutputStream fileOut = new FileOutputStream(dataFile);
ByteArrayOutputStream out = new ByteArrayOutputStream();
FileInputStream fileIn = new FileInputStream(dataFile);
String writeData1 = "test data";
int writeData2 = 10;
List<String> writeData3 = new ArrayList<String>();
writeData3.add("list data1");
writeData3.add("list data1");
ObjectMapper mapper = new ObjectMapper();
byte[] writeData1Bytes = mapper.writeValueAsBytes(writeData1);
out.write(writeData1Bytes);
byte[] writeData2Bytes = mapper.writeValueAsBytes(writeData2);
out.write(writeData2Bytes);
byte[] writeData3Bytes = mapper.writeValueAsBytes(writeData3);
out.write(writeData3Bytes);
out.writeTo(fileOut);
// TODO: How to deserialize?
int pos = 0;
byte[] readData = new byte[1000];
fileIn.read(readData);
String readData1 = mapper.readValue(readData, pos, writeData1Bytes.length, String.class);
pos += writeData1Bytes.length;
Integer readData2 = mapper.readValue(readData, pos, writeData2Bytes.length, Integer.class);
pos += writeData2Bytes.length;
ArrayList readData3 = mapper.readValue(readData, pos, writeData3Bytes.length, ArrayList.class);
pos += writeData3Bytes.length;
System.out.printf("readData1 = %s%n", readData1);
System.out.printf("readData2 = %s%n", readData2);
System.out.printf("readData3 = %s%n", readData3);
the file looks then like this
"test data"10["list data1","list data1"]
How to do it correctly
a way more elegant way is to encapsulate your data in an object which can be turned into a valid JSON string and from that Jackson won't need any more information
public class JacksonTest {
public static class DataNode {
#JsonProperty("data1")
private String data1;
#JsonProperty("data2")
private int data2;
#JsonProperty("data3")
private List<String> data3;
//needed for Jackson
public DataNode() {
}
public DataNode(String data1, int data2, List<String> data3) {
this.data1 = data1;
this.data2 = data2;
this.data3 = data3;
}
}
public static void main(String[] args) throws Exception {
File dataFile = new File("jackson.txt");
if(!dataFile.exists())
dataFile.createNewFile();
FileOutputStream fileOut = new FileOutputStream(dataFile);
ByteArrayOutputStream out = new ByteArrayOutputStream();
FileInputStream fileIn = new FileInputStream(dataFile);
String writeData1 = "test data";
int writeData2 = 10;
List<String> writeData3 = new ArrayList<String>();
writeData3.add("list data1");
writeData3.add("list data1");
DataNode writeData = new DataNode(writeData1, writeData2, writeData3);
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(out, writeData);
out.writeTo(fileOut);
// TODO: How to deserialize?
DataNode readData = mapper.readValue(fileIn, DataNode.class);
System.out.printf("readData1 = %s%n", readData.data1);
System.out.printf("readData2 = %s%n", readData.data2);
System.out.printf("readData3 = %s%n", readData.data3);
}
}
the content of the file looks like this
{"data1":"test data","data2":10,"data3":["list data1","list data1"]}
You'll want to use one of the readValue methods from ObjectMapper - probably one that has a Reader or InputStream as the first parameter.
#Japu_D_Cret Thank you for such a detailed answer!
Actually I want to use msgpack to transfer data, and I made it work by using msgpack, here is my code
ByteArrayOutputStream out = new ByteArrayOutputStream();
String data1 = "test data";
int data2 = 10;
List<String> data3 = new ArrayList<String>();
data3.add("list data1");
data3.add("list data1");
MessagePack packer = new MessagePack();
packer.write(out, data1);
packer.write(out, data2);
packer.write(out, data3);
// TODO: How to deserialize?
BufferUnpacker unpacker = packer.createBufferUnpacker(out.toByteArray());
System.out.println(unpacker.readString());
System.out.println(unpacker.readInt());
System.out.println(unpacker.read(Templates.tList(Templates.TString)));
Then I found jackson-databind on msgpack website and it supports msgpack format also.
I do some tests on these two and found that jackson's serialize performance is better than msgpack, so I want to use jackson instead of msgpack.
I'm having a text file with label and tweets .
positive,I love this car
negative,I hate this book
positive,Good product.
I need to convert each line into vector value.If i use seq2sparse command means the whole document gets converted to vector,but i need to convert each line as vector not the whole document.
ex :
key : positive value : vectorvalue(tweet)
How can we achieve this in mahout?
/* Here is what i have done */
StringTokenizer str= new StringTokenizer(line,",");
String label=str.nextToken();
while (str.hasMoreTokens())
{
tweetline =str.nextToken();
System.out.println("Tweetline"+tweetline);
StringTokenizer words = new StringTokenizer(tweetline," ");
while(words.hasMoreTokens()){
featureList.add(words.nextToken());}
}
Vector unclassifiedInstanceVector = new RandomAccessSparseVector(tweetline.split(" ").length);
FeatureVectorEncoder vectorEncoder = new AdaptiveWordValueEncoder(label);
vectorEncoder.setProbes(1);
System.out.println("Feature List: "+featureList);
for (Object feature: featureList) {
vectorEncoder.addToVector((String) feature, unclassifiedInstanceVector);
}
context.write(new Text("/"+label), new VectorWritable(unclassifiedInstanceVector));
Thanks in advance
You can write it to app hdfs path with SequenceFile.Writer
FS = FileSystem.get(HBaseConfiguration.create());
String newPath = "/foo/mahouttest/part-r-00000";
Path newPathFile = new Path(newPath);
Text key = new Text();
VectorWritable value = new VectorWritable();
SequenceFile.Writer writer = SequenceFile.createWriter(FS, conf, newPathFile,
key.getClass(), value.getClass());
.....
key.set("c/"+label);
value.set(unclassifiedInstanceVector );
writer.append(key,value);
I want to use jackson to convert a ArrayList to a JsonArray.
Event.java : this is the java bean class with two fields "field1", "field2" mapped as JsonProperty.
My goal is:
Convert
ArrayList<Event> list = new ArrayList<Event>();
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
To
[
{"field1":"a1", "field":"a2"},
{"field1":"b1", "field":"b2"}
]
The way I can think of is:
writeListToJsonArray():
public void writeListToJsonArray() throws IOException {
ArrayList<Event> list = new ArrayList<Event>();
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
OutputStream out = new ByteArrayOutputStream();
JsonFactory jfactory = new JsonFactory();
JsonGenerator jGenerator = jfactory.createJsonGenerator(out, JsonEncoding.UTF8);
ObjectMapper mapper = new ObjectMapper();
jGenerator.writeStartArray(); // [
for (Event event : list) {
String e = mapper.writeValueAsString(event);
jGenerator.writeRaw(usage);
// here, big hassles to write a comma to separate json objects, when the last object in the list is reached, no comma
}
jGenerator.writeEndArray(); // ]
jGenerator.close();
System.out.println(out.toString());
}
I am looking for something like:
generator.write(out, list)
this directly convert the list to json array format and then write it to outputstream "out".
even greedier:
generator.write(out, list1)
generator.write(out, list2)
this will just convert/add in the list1, list2 into a single json array. then write it to "out"
This is overly complicated, Jackson handles lists via its writer methods just as well as it handles regular objects. This should work just fine for you, assuming I have not misunderstood your question:
public void writeListToJsonArray() throws IOException {
final List<Event> list = new ArrayList<Event>(2);
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
final ByteArrayOutputStream out = new ByteArrayOutputStream();
final ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(out, list);
final byte[] data = out.toByteArray();
System.out.println(new String(data));
}
I can't find toByteArray() as #atrioom said, so I use StringWriter, please try:
public void writeListToJsonArray() throws IOException {
//your list
final List<Event> list = new ArrayList<Event>(2);
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
final StringWriter sw =new StringWriter();
final ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(sw, list);
System.out.println(sw.toString());//use toString() to convert to JSON
sw.close();
}
Or just use ObjectMapper#writeValueAsString:
final ObjectMapper mapper = new ObjectMapper();
System.out.println(mapper.writeValueAsString(list));
In objectMapper we have writeValueAsString() which accepts object as parameter. We can pass object list as parameter get the string back.
List<Apartment> aptList = new ArrayList<Apartment>();
Apartment aptmt = null;
for(int i=0;i<5;i++){
aptmt= new Apartment();
aptmt.setAptName("Apartment Name : ArrowHead Ranch");
aptmt.setAptNum("3153"+i);
aptmt.setPhase((i+1));
aptmt.setFloorLevel(i+2);
aptList.add(aptmt);
}
mapper.writeValueAsString(aptList)