空安全编程的典范：Java 8中的安全应用指南 - ToB企服应用市场:ToB评测及商务社交产业平台

public static void main(String[] args) {
// 原始字符串
String originalInput = "Hello World!";
// 编码为Base64
String encodedString = Base64.getEncoder().encodeToString(originalInput.getBytes());
System.out.println("Encoded string: " + encodedString);
// 解码Base64
byte[] decodedBytes = Base64.getDecoder().decode(encodedString);
String decodedString = new String(decodedBytes);
System.out.println("Decoded string: " + decodedString);
}
// 输出
Encoded string: SGVsbG8gV29ybGQh
Decoded string: Hello World!

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public static void main(String[] args) throws UnsupportedEncodingException {
// 原始字符串
String originalInput = "Hello World!";
// URL 和文件名安全的 Base64 编码
String encodedString = Base64.getUrlEncoder().encodeToString(originalInput.getBytes("utf-8"));
System.out.println("Encoded string (URL safe): " + encodedString);
// 解码 URL 和文件名安全的 Base64
byte[] decodedBytes = Base64.getUrlDecoder().decode(encodedString);
String decodedString = new String(decodedBytes, "utf-8");
System.out.println("Decoded string: " + decodedString);
}
// 输出
Encoded string (URL safe): SGVsbG8gV29ybGQh
Decoded string: Hello World!

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public static void main(String[] args) throws UnsupportedEncodingException {
// 原始字符串
String originalInput = "Hello World!";
// MIME Base64 编码
String encodedString = Base64.getMimeEncoder().encodeToString(originalInput.getBytes("utf-8"));
System.out.println("Encoded string (MIME):" + encodedString);
// 解码 MIME Base64
byte[] decodedBytes = Base64.getMimeDecoder().decode(encodedString);
String decodedString = new String(decodedBytes, "utf-8");
System.out.println("Decoded string: " + decodedString);
}
// 输出
Encoded string (MIME):SGVsbG8gV29ybGQh
Decoded string: Hello World!

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public static void main(String[] args) {
// 创建一个包含非空值的 Optional 对象
Optional<String> optional1 = Optional.of("Hello");
System.out.println("Optional 1 value: " + optional1.get());
// 创建一个可能为 null 的 Optional 对象
String nullableValue = null;
Optional<String> optional2 = Optional.ofNullable(nullableValue);
System.out.println("Optional 2 is present? " + optional2.isPresent());
// 获取 Optional 对象中的值
String value = optional1.get();
System.out.println("Value: " + value);
// 检查 Optional 对象中是否有值
if (optional1.isPresent()) {
System.out.println("Optional contains value.");
} else {
System.out.println("Optional is empty.");
}
// 使用 orElse 提供默认值
String result1 = optional2.orElse("Default Value");
System.out.println("Result 1: " + result1);
// 使用 orElseGet 提供默认值
String result2 = optional2.orElseGet(() -> {
// 处理逻辑，返回默认值
return "Default Value from Supplier";
});
System.out.println("Result 2: " + result2);
// 如果 Optional 对象中有值，则执行操作
optional1.ifPresent(val -> System.out.println("Value is present: " + val));
// 过滤值
Optional<String> filteredOptional = optional1.filter(val -> val.startsWith("H"));
System.out.println("Filtered Optional value: " + filteredOptional.orElse("Not found"));
// 映射值
Optional<String> transformedOptional = optional1.map(val -> val.toUpperCase());
System.out.println("Transformed Optional value: " + transformedOptional.orElse("No value"));
// 抛出异常
try {
value = optional2.orElseThrow(() -> new IllegalArgumentException("Value is required."));
System.out.println("Value: " + value);
} catch (IllegalArgumentException e) {
System.out.println("Exception: " + e.getMessage());
}
}
// 输出
Optional 1 value: Hello
Optional 2 is present? false
Value: Hello
Optional contains value.
Result 1: Default Value
Result 2: Default Value from Supplier
Value is present: Hello
Filtered Optional value: Hello
Transformed Optional value: HELLO
Exception: Value is required.

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public static void main(String[] args) throws Exception {
// 创建 Nashorn 脚本引擎
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
// 执行 JavaScript 代码
engine.eval("print('Hello Nashorn!')");
}

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public static void main(String[] args) throws Exception {
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
// 将 Java 变量传递给 JavaScript
engine.put("name", "Alice");
engine.eval("print('Hello, ' + name + '!')");
}

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// Java 类
public class Person {
public String getName() {
return "Alice";
}
}
// JavaScript 代码
engine.eval("var person = new Person(); print(person.getName());");

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$ jjs script.js

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