diff --git a/pom.xml b/pom.xml
index a75bb37..f2bcbf3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
top.gtb520.java.gnu
gnu_java_utils_library
- 1.5-SNAPSHOT
+ 1.6-SNAPSHOT
25
diff --git a/src/main/java/top/gtb520/java/gnu/java/utils/library/main.java b/src/main/java/top/gtb520/java/gnu/java/utils/library/main.java
index 187bea1..b54840d 100644
--- a/src/main/java/top/gtb520/java/gnu/java/utils/library/main.java
+++ b/src/main/java/top/gtb520/java/gnu/java/utils/library/main.java
@@ -1,6 +1,7 @@
package top.gtb520.java.gnu.java.utils.library;
import top.gtb520.java.gnu.java.utils.library.utils.print.ColorNameEnum;
+import top.gtb520.java.gnu.java.utils.library.utils.compress.CompressPNG.PNGThreshold;
import java.io.File;
import java.nio.file.Path;
@@ -31,6 +32,11 @@ public interface main {
static void UnZip(String sourceFilePanth, String destFilePanth) throws Exception {
top.gtb520.java.gnu.java.utils.library.utils.compress.compress.UnZip(sourceFilePanth, destFilePanth);
}
+
+ // 压缩png图片
+ static File CompressPNG(File pngFile, PNGThreshold threshold) {
+ return top.gtb520.java.gnu.java.utils.library.utils.compress.CompressPNG.PNG(pngFile, threshold);
+ }
}
// 终端打印接口与方法
diff --git a/src/main/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNG.java b/src/main/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNG.java
index 9ff52c8..3d1a9dd 100644
--- a/src/main/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNG.java
+++ b/src/main/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNG.java
@@ -1,4 +1,82 @@
package top.gtb520.java.gnu.java.utils.library.utils.compress;
+import javax.imageio.IIOImage;
+import javax.imageio.ImageIO;
+import javax.imageio.ImageWriteParam;
+import javax.imageio.ImageWriter;
+import javax.imageio.stream.ImageOutputStream;
+import java.io.File;
+import java.awt.image.BufferedImage;
+import java.util.Iterator;
+
public class CompressPNG {
+ /***
+ * 压缩PNG图片
+ * 传入未压缩的PNG图片文件，和压缩阈值，返回压缩后的PNG图片文件
+ * 5个等级的压缩阈值，从低到高，THRESHOLD_1 最低，THRESHOLD_5 最高
+ *
+ * @param pngFile 未压缩的PNG图片文件
+ * @param threshold 压缩阈值
+ * @return 压缩后的PNG图片文件
+ */
+ public static File PNG(File pngFile, PNGThreshold threshold) {
+ if (!pngFile.exists()) {
+ System.out.println("文件不存在");
+ return null;
+ }
+ if (pngFile.getName().endsWith(".png") || pngFile.getName().endsWith(".PNG")) {
+ try {
+ BufferedImage image = ImageIO.read(pngFile);
+ if (image == null) {
+ System.out.println("无法读取PNG文件");
+ return null;
+ }
+
+ Iterator writers = ImageIO.getImageWritersByFormatName("png");
+ if (!writers.hasNext()) {
+ System.out.println("未找到PNG写入器");
+ return null;
+ }
+ ImageWriter writer = writers.next();
+
+ try (ImageOutputStream ios = ImageIO.createImageOutputStream(pngFile)) {
+ writer.setOutput(ios);
+
+ ImageWriteParam param = writer.getDefaultWriteParam();
+ param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
+ param.setCompressionQuality(getCompressionQuality(threshold));
+
+ writer.write(null, new IIOImage(image, null, null), param);
+ } finally {
+ writer.dispose();
+ }
+
+ return pngFile;
+ } catch (Exception e) {
+ e.printStackTrace();
+ return null;
+ }
+ } else {
+ System.out.println("文件不是PNG格式，无法压缩");
+ }
+ return null;
+ }
+
+ private static float getCompressionQuality(PNGThreshold threshold) {
+ return switch (threshold) {
+ case THRESHOLD_1 -> 0.7f;
+ case THRESHOLD_2 -> 0.5f;
+ case THRESHOLD_3 -> 0.3f;
+ case THRESHOLD_4 -> 0.1f;
+ case THRESHOLD_5 -> 0.0f;
+ };
+ }
+
+ public enum PNGThreshold {
+ THRESHOLD_1,
+ THRESHOLD_2,
+ THRESHOLD_3,
+ THRESHOLD_4,
+ THRESHOLD_5;
+ }
}
diff --git a/src/test/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNGTest.java b/src/test/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNGTest.java
new file mode 100644
index 0000000..11ff033
--- /dev/null
+++ b/src/test/java/top/gtb520/java/gnu/java/utils/library/utils/compress/CompressPNGTest.java
@@ -0,0 +1,205 @@
+package top.gtb520.java.gnu.java.utils.library.utils.compress;
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+
+public class CompressPNGTest {
+
+ static int passed = 0;
+ static int failed = 0;
+
+ public static void main(String[] args) {
+ System.out.println("========== CompressPNG 测试开始 ==========");
+
+ testCompressWithEachThreshold();
+ testNonPNGFile();
+ testNonExistentFile();
+ testCompressedFileIsValidPNG();
+ testCompressedFileSmallerOrEqual();
+
+ System.out.println("========================================");
+ System.out.println("测试完成: 通过 " + passed + ", 失败 " + failed);
+ if (failed > 0) {
+ System.exit(1);
+ }
+ }
+
+ /**
+ * 测试每个压缩阈值均能正常压缩并返回原文件
+ */
+ static void testCompressWithEachThreshold() {
+ String testName = "testCompressWithEachThreshold";
+ for (CompressPNG.PNGThreshold threshold : CompressPNG.PNGThreshold.values()) {
+ File pngFile = null;
+ try {
+ pngFile = createTestPNG("test_threshold_" + threshold.name());
+ long originalSize = pngFile.length();
+
+ File result = CompressPNG.PNG(pngFile, threshold);
+
+ boolean returnedSameFile = result != null && result.equals(pngFile);
+ assertCondition(testName + " [" + threshold.name() + "] - 应返回原文件引用", returnedSameFile);
+
+ boolean fileExists = result != null && result.exists() && result.length() > 0;
+ assertCondition(testName + " [" + threshold.name() + "] - 压缩后文件应存在且非空", fileExists);
+
+ System.out.println(" [" + threshold.name() + "] 原始: " + originalSize + " bytes, 压缩后: " + (result != null ? result.length() : "N/A") + " bytes");
+ } catch (Exception e) {
+ assertCondition(testName + " [" + threshold.name() + "] - 不应抛出异常: " + e.getMessage(), false);
+ } finally {
+ deleteTestFile(pngFile);
+ }
+ }
+ }
+
+ /**
+ * 测试传入非PNG文件应返回null
+ */
+ static void testNonPNGFile() {
+ String testName = "testNonPNGFile";
+ File txtFile = null;
+ try {
+ txtFile = File.createTempFile("test_not_png", ".txt");
+ java.nio.file.Files.writeString(txtFile.toPath(), "this is not a png");
+
+ File result = CompressPNG.PNG(txtFile, CompressPNG.PNGThreshold.THRESHOLD_3);
+ assertCondition(testName + " - 非PNG文件应返回null", result == null);
+ } catch (Exception e) {
+ assertCondition(testName + " - 不应抛出异常: " + e.getMessage(), false);
+ } finally {
+ deleteTestFile(txtFile);
+ }
+ }
+
+ /**
+ * 测试传入不存在的文件应返回null
+ */
+ static void testNonExistentFile() {
+ String testName = "testNonExistentFile";
+ try {
+ File nonExistent = new File(System.getProperty("java.io.tmpdir"), "non_existent_file.png");
+ File result = CompressPNG.PNG(nonExistent, CompressPNG.PNGThreshold.THRESHOLD_3);
+ assertCondition(testName + " - 不存在的文件应返回null", result == null);
+ } catch (Exception e) {
+ assertCondition(testName + " - 不应抛出异常: " + e.getMessage(), false);
+ }
+ }
+
+ /**
+ * 测试压缩后的文件仍然是有效的PNG图片
+ */
+ static void testCompressedFileIsValidPNG() {
+ String testName = "testCompressedFileIsValidPNG";
+ File pngFile = null;
+ try {
+ pngFile = createTestPNG("test_valid_png");
+ CompressPNG.PNG(pngFile, CompressPNG.PNGThreshold.THRESHOLD_3);
+
+ BufferedImage compressed = ImageIO.read(pngFile);
+ boolean isValidPNG = compressed != null;
+ assertCondition(testName + " - 压缩后的文件应是有效的PNG图片", isValidPNG);
+
+ if (isValidPNG) {
+ assertCondition(testName + " - 压缩后图片宽度应一致", compressed.getWidth() == 100);
+ assertCondition(testName + " - 压缩后图片高度应一致", compressed.getHeight() == 100);
+ }
+ } catch (Exception e) {
+ assertCondition(testName + " - 不应抛出异常: " + e.getMessage(), false);
+ } finally {
+ deleteTestFile(pngFile);
+ }
+ }
+
+ /**
+ * 测试压缩后文件大小不超过原始文件
+ */
+ static void testCompressedFileSmallerOrEqual() {
+ String testName = "testCompressedFileSmallerOrEqual";
+ File pngFile = null;
+ try {
+ // 创建一个较大的、有压缩空间的测试图片（纯色+渐变）
+ pngFile = createLargeTestPNG("test_compression_ratio", 500, 500);
+ long originalSize = pngFile.length();
+
+ File result = CompressPNG.PNG(pngFile, CompressPNG.PNGThreshold.THRESHOLD_5);
+
+ if (result != null) {
+ long compressedSize = result.length();
+ assertCondition(testName + " - 压缩后文件大小(" + compressedSize + ")应不超过原始大小(" + originalSize + ")",
+ compressedSize <= originalSize);
+ System.out.println(" 原始: " + originalSize + " bytes, THRESHOLD_5压缩后: " + compressedSize + " bytes");
+ } else {
+ assertCondition(testName + " - 压缩不应返回null", false);
+ }
+ } catch (Exception e) {
+ assertCondition(testName + " - 不应抛出异常: " + e.getMessage(), false);
+ } finally {
+ deleteTestFile(pngFile);
+ }
+ }
+
+ // ========== 辅助方法 ==========
+
+ /**
+ * 创建一个100x100的测试PNG图片
+ */
+ static File createTestPNG(String name) throws IOException {
+ File file = File.createTempFile(name, ".png");
+ BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);
+ Graphics2D g2d = image.createGraphics();
+ // 绘制渐变图案，使图片有一定的压缩空间
+ for (int y = 0; y < 100; y++) {
+ for (int x = 0; x < 100; x++) {
+ image.setRGB(x, y, new Color(x * 2, y * 2, (x + y)).getRGB());
+ }
+ }
+ g2d.dispose();
+ ImageIO.write(image, "png", file);
+ return file;
+ }
+
+ /**
+ * 创建一个指定尺寸的测试PNG图片（包含更多颜色变化以增加压缩效果差异）
+ */
+ static File createLargeTestPNG(String name, int width, int height) throws IOException {
+ File file = File.createTempFile(name, ".png");
+ BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
+ Graphics2D g2d = image.createGraphics();
+ // 绘制大面积纯色区域（压缩率高）
+ g2d.setColor(Color.WHITE);
+ g2d.fillRect(0, 0, width, height);
+ g2d.setColor(Color.RED);
+ g2d.fillRect(0, 0, width / 2, height / 2);
+ g2d.setColor(Color.BLUE);
+ g2d.fillRect(width / 2, 0, width / 2, height / 2);
+ g2d.setColor(Color.GREEN);
+ g2d.fillRect(0, height / 2, width / 2, height / 2);
+ g2d.setColor(Color.YELLOW);
+ g2d.fillRect(width / 2, height / 2, width / 2, height / 2);
+ g2d.dispose();
+ ImageIO.write(image, "png", file);
+ return file;
+ }
+
+ /**
+ * 安全删除测试文件
+ */
+ static void deleteTestFile(File file) {
+ if (file != null && file.exists()) {
+ file.delete();
+ }
+ }
+
+ static void assertCondition(String message, boolean condition) {
+ if (condition) {
+ System.out.println("[PASS] " + message);
+ passed++;
+ } else {
+ System.out.println("[FAIL] " + message);
+ failed++;
+ }
+ }
+}