java - 无法使用 Ghost4J 加载库 'gs'

Question

我正在尝试使用 Ghost4J 将 PDF 转换为 PNG。我知道人们以前问过这个问题，但不是在 OS X 10 和最新版本的 Ghost4J 中。

我已按照此处 zippy1978 的回答中列出的说明进行操作:PDF to image using Java

我已经关注了 Ghost4J page 中的所有内容

我也尝试过这里的两个答案:How can i use ghost4j on OS X 10.9

我已经用 Port 安装了 Ghostscript并尝试过 Richard Koch's website .

我继续收到此错误:

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Handler processing failed; nested exception is java.lang.UnsatisfiedLinkError: Unable to load library 'gs': dlopen(libgs.dylib, 9): image not found] with root cause

java.lang.UnsatisfiedLinkError: Unable to load library 'gs': dlopen(libgs.dylib, 9): image not found
    at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:166)
    at com.sun.jna.NativeLibrary.getInstance(NativeLibrary.java:239)
    at com.sun.jna.Library$Handler.<init>(Library.java:140)
    at com.sun.jna.Native.loadLibrary(Native.java:393)
    at com.sun.jna.Native.loadLibrary(Native.java:378)
    at org.ghost4j.GhostscriptLibraryLoader.loadLibrary(GhostscriptLibraryLoader.java:39)
    at org.ghost4j.GhostscriptLibrary.<clinit>(GhostscriptLibrary.java:34)
    at org.ghost4j.Ghostscript.initialize(Ghostscript.java:323)
    at org.ghost4j.renderer.SimpleRenderer.run(SimpleRenderer.java:105)
    at org.ghost4j.renderer.AbstractRemoteRenderer.render(AbstractRemoteRenderer.java:86)
    at org.ghost4j.renderer.AbstractRemoteRenderer.render(AbstractRemoteRenderer.java:70)
    at com.xxxx.yyyy.controller.rest.yyyyyController.zzzz(yyyyyController.java:182)

我在这里缺少什么？

来自我的 Controller 崩溃的代码是这样的(我标记了该行):

// imgSrc is the PDF in Base 64 and output file is a File

byte[] imageByte;
BASE64Decoder decoder = new BASE64Decoder();
imageByte = decoder.decodeBuffer(imgSrc);
outputfile = new File("image.pdf");
OutputStream fop = new FileOutputStream(outputfile);
fop.write(imageByte);
fop.flush();
fop.close();
PDFDocument document = new PDFDocument();
document.load(outputfile);
SimpleRenderer renderer = new SimpleRenderer();
renderer.setResolution(300);
List images = renderer.render(document);       //CRASH TAKES PLACE HERE ***
outputfile = new File("image.png");
ImageIO.write((RenderedImage) images.get(0), "png", outputfile);

Answer 1

所以我想通了!
我在这个 conversation 中找到了答案:

I had the same problem, although I had installed macports package "ghostscript" already. Setting LD_LIBRARY_PATH helped:

$ export LD_LIBRARY_PATH=/opt/local/lib

这导致了警告消息:

log4j:WARN No appenders could be found for logger (slideselector.facedata.FaceDataParser).
log4j:WARN Please initialize the log4j system properly.

这是在以下人员的帮助下解决的:How to initialize log4j properly?

For all maven guys like me: put the log4j.properties into src/main/resources