Java中可以使用壓縮算法對字符串進行壓縮傳輸，常用的壓縮方法有以下幾種：

1. GZIP壓縮：可以使用Java的GZIPOutputStream類進行壓縮，使用GZIPInputStream類進行解壓縮。可以使用以下代碼進行壓縮和解壓縮：

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZIPCompression {
    public static byte[] compress(String data) throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        GZIPOutputStream gzip = new GZIPOutputStream(bos);
        gzip.write(data.getBytes("UTF-8"));
        gzip.close();
        byte[] compressedData = bos.toByteArray();
        bos.close();
        return compressedData;
    }

    public static String decompress(byte[] compressedData) throws IOException {
        ByteArrayInputStream bis = new ByteArrayInputStream(compressedData);
        GZIPInputStream gzip = new GZIPInputStream(bis);
        byte[] buffer = new byte[1024];
        StringBuilder sb = new StringBuilder();
        int len;
        while ((len = gzip.read(buffer)) != -1) {
            sb.append(new String(buffer, 0, len, "UTF-8"));
        }
        gzip.close();
        bis.close();
        return sb.toString();
    }

    public static void main(String[] args) throws IOException {
        String originalString = "This is a test string";
        byte[] compressedData = compress(originalString);
        String decompressedString = decompress(compressedData);
        System.out.println("Original string: " + originalString);
        System.out.println("Compressed data: " + new String(compressedData));
        System.out.println("Decompressed string: " + decompressedString);
    }
}

2. Deflater壓縮：可以使用Java的Deflater類進行壓縮，使用Inflater類進行解壓縮。可以使用以下代碼進行壓縮和解壓縮：

import java.io.ByteArrayOutputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

public class DeflaterCompression {
    public static byte[] compress(String data) throws IOException {
        byte[] input = data.getBytes("UTF-8");
        Deflater deflater = new Deflater();
        deflater.setInput(input);
        ByteArrayOutputStream bos = new ByteArrayOutputStream(input.length);
        deflater.finish();
        byte[] buffer = new byte[1024];
        while (!deflater.finished()) {
            int count = deflater.deflate(buffer);
            bos.write(buffer, 0, count);
        }
        bos.close();
        byte[] compressedData = bos.toByteArray();
        return compressedData;
    }

    public static String decompress(byte[] compressedData) throws IOException {
        Inflater inflater = new Inflater();
        inflater.setInput(compressedData);
        ByteArrayOutputStream bos = new ByteArrayOutputStream(compressedData.length);
        byte[] buffer = new byte[1024];
        while (!inflater.finished()) {
            int count = inflater.inflate(buffer);
            bos.write(buffer, 0, count);
        }
        bos.close();
        byte[] decompressedData = bos.toByteArray();
        return new String(decompressedData, "UTF-8");
    }

    public static void main(String[] args) throws IOException {
        String originalString = "This is a test string";
        byte[] compressedData = compress(originalString);
        String decompressedString = decompress(compressedData);
        System.out.println("Original string: " + originalString);
        System.out.println("Compressed data: " + new String(compressedData));
        System.out.println("Decompressed string: " + decompressedString);
    }
}

這些方法可以將字符串進行壓縮，然后傳輸。在接收端，再進行解壓縮操作，恢復原始字符串。