2021年在Kotlin回答。

编码:

val data: String = "Hello"
val dataByteArray: ByteArray = data.toByteArray()
val dataInBase64: String = Base64Utils.encode(dataByteArray)

解码:

val dataInBase64: String = "..."
val dataByteArray: ByteArray = Base64Utils.decode(dataInBase64)
val data: String = dataByteArray.toString()

加密:

byte[] encrpt= text.getBytes("UTF-8");
String base64 = Base64.encodeToString(encrpt, Base64.DEFAULT);

解密:

byte[] decrypt= Base64.decode(base64, Base64.DEFAULT);
String text = new String(decrypt, "UTF-8");

第一:

选择编码。UTF-8通常是一个不错的选择;坚持对两边都有效的编码。很少使用UTF-8或UTF-16以外的代码。

发送端:

将字符串编码为字节(例如text.getBytes(encodingName)) 使用base64类将字节编码为base64 传输base64

接收端:

接收base64 使用base64类将base64解码为字节 解码字节为字符串(例如new string (bytes, encodingName))

比如:

// Sending side
byte[] data = text.getBytes("UTF-8");
String base64 = Base64.encodeToString(data, Base64.DEFAULT);

// Receiving side
byte[] data = Base64.decode(base64, Base64.DEFAULT);
String text = new String(data, "UTF-8");

或者使用StandardCharsets:

// Sending side
byte[] data = text.getBytes(StandardCharsets.UTF_8);
String base64 = Base64.encodeToString(data, Base64.DEFAULT);

// Receiving side
byte[] data = Base64.decode(base64, Base64.DEFAULT);
String text = new String(data, StandardCharsets.UTF_8);

基于之前的答案，我使用以下实用程序方法，以防有人想使用它。

    /**
 * @param message the message to be encoded
 *
 * @return the enooded from of the message
 */
public static String toBase64(String message) {
    byte[] data;
    try {
        data = message.getBytes("UTF-8");
        String base64Sms = Base64.encodeToString(data, Base64.DEFAULT);
        return base64Sms;
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }

    return null;
}

/**
 * @param message the encoded message
 *
 * @return the decoded message
 */
public static String fromBase64(String message) {
    byte[] data = Base64.decode(message, Base64.DEFAULT);
    try {
        return new String(data, "UTF-8");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }

    return null;
}

package net.itempire.virtualapp;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Base64;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class BaseActivity extends AppCompatActivity {
EditText editText;
TextView textView;
TextView textView2;
TextView textView3;
TextView textView4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_base);
        editText=(EditText)findViewById(R.id.edt);
        textView=(TextView) findViewById(R.id.tv1);
        textView2=(TextView) findViewById(R.id.tv2);
        textView3=(TextView) findViewById(R.id.tv3);
        textView4=(TextView) findViewById(R.id.tv4);
        textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
             textView2.setText(Base64.encodeToString(editText.getText().toString().getBytes(),Base64.DEFAULT));
            }
        });

        textView3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                textView4.setText(new String(Base64.decode(textView2.getText().toString(),Base64.DEFAULT)));

            }
        });


    }
}

26级火警

String encodedString = Base64.getEncoder().encodeToString(byteArray);

裁判: https://developer.android.com/reference/java/util/Base64.Encoder.html encodeToString (byte [])