问题解决：com.lowagie.text.DocumentException: Font 'STSong-Light' with 'UniGB-UCS2-H'

正确jar包引入：（这里的版本号无所谓，下同）

	com.itextpdf
	itext-asian
	5.2.0


	com.itextpdf
	itextpdf
	5.4.3

不要引入的jar

	com.lowagie
	itext
	2.1.7

关键点在于：使用com.lowagie.text.pdf.BaseFont还是com.itextpdf.text.pdf.BaseFont

BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);

com.lowagie.text.pdf.BaseFont

这里我们先看一下com.lowagie.text.pdf.BaseFont的源码，为何会报错：Font ‘STSong-Light’ with ‘UniGB-UCS2-H’

public static BaseFont createFont(String var0, String var1, boolean var2) throws DocumentException, IOException {
    return createFont(var0, var1, var2, true, (byte[])null, (byte[])null, false);
}

public static BaseFont createFont(String var0, String var1, boolean var2, boolean var3) throws DocumentException, IOException {
    return createFont(var0, var1, var2, true, (byte[])null, (byte[])null, var3);
}

public static BaseFont createFont(String var0, String var1, boolean var2, boolean var3, byte[] var4, byte[] var5) throws DocumentException, IOException {
    return createFont(var0, var1, var2, var3, var4, var5, false);
}

public static BaseFont createFont(String var0, String var1, boolean var2, boolean var3, byte[] var4, byte[] var5, boolean var6) throws DocumentException, IOException {
    return createFont(var0, var1, var2, var3, var4, var5, false, false);
}

public static BaseFont createFont(String var0, String var1, boolean var2, boolean var3, byte[] var4, byte[] var5, boolean var6, boolean var7) throws DocumentException, IOException {
    String var8 = getBaseName(var0);
    var1 = normalizeEncoding(var1);
    //var9=false,详解如下
    boolean var9 = BuiltinFonts14.containsKey(var0);//看这里
    //var10=false,详解如下
    boolean var10 = var9 ? false : CJKFont.isCJKFont(var8, var1);//看这里
    if (!var9 && !var10) {
        if (var1.equals("Identity-H") || var1.equals("Identity-V")) {
            var2 = true;
        }
    } else {
        var2 = false;
    }
    ....
    //
    if (!var9 && !var0.toLowerCase().endsWith(".afm") && !var0.toLowerCase().endsWith(".pfm")) {
            if (!var8.toLowerCase().endsWith(".ttf") && !var8.toLowerCase().endsWith(".otf") && var8.toLowerCase().indexOf(".ttc,") <= 0) {
                if (!var10) {
                    if (var6) {
                        return null;
                    }
					//进入到这里直接跑异常
                    throw new DocumentException("Font '" + var0 + "' with '" + var1 + "' is not recognized.");
                }
    ....
}

这里我们注意下BuiltinFonts14.containsKey(var0);

protected static final HashMap BuiltinFonts14 = new HashMap();

static {
    BuiltinFonts14.put("Courier", PdfName.COURIER);
    BuiltinFonts14.put("Courier-Bold", PdfName.COURIER_BOLD);
    BuiltinFonts14.put("Courier-BoldOblique", PdfName.COURIER_BOLDOBLIQUE);
    BuiltinFonts14.put("Courier-Oblique", PdfName.COURIER_OBLIQUE);
    BuiltinFonts14.put("Helvetica", PdfName.HELVETICA);
    BuiltinFonts14.put("Helvetica-Bold", PdfName.HELVETICA_BOLD);
    BuiltinFonts14.put("Helvetica-BoldOblique", PdfName.HELVETICA_BOLDOBLIQUE);
    BuiltinFonts14.put("Helvetica-Oblique", PdfName.HELVETICA_OBLIQUE);
    BuiltinFonts14.put("Symbol", PdfName.SYMBOL);
    BuiltinFonts14.put("Times-Roman", PdfName.TIMES_ROMAN);
    BuiltinFonts14.put("Times-Bold", PdfName.TIMES_BOLD);
    BuiltinFonts14.put("Times-BoldItalic", PdfName.TIMES_BOLDITALIC);
    BuiltinFonts14.put("Times-Italic", PdfName.TIMES_ITALIC);
    BuiltinFonts14.put("ZapfDingbats", PdfName.ZAPFDINGBATS);
}

所以BuiltinFonts14.containsKey(“STSong-Light”)返回false
注意CJKFont.isCJKFont(var8, var1)这个方法；我们进CJKFont看一下

public static boolean isCJKFont(String var0, String var1) {
    loadProperties();//看这里
    String var2 = cjkFonts.getProperty(var0);
    return var2 != null && (var1.equals("Identity-H") || var1.equals("Identity-V") || var2.indexOf("_" + var1 + "_") >= 0);
}
private static void loadProperties() {
    if (!propertiesLoaded) {
        Hashtable var0 = allFonts;
        synchronized(allFonts) {
            if (!propertiesLoaded) {
                try {
                    InputStream var1 = getResourceStream("com/lowagie/text/pdf/fonts/cjkfonts.properties");
                    cjkFonts.load(var1);
                    var1.close();
                    var1 = getResourceStream("com/lowagie/text/pdf/fonts/cjkencodings.properties");
                    cjkEncodings.load(var1);
                    var1.close();
                } catch (Exception var3) {
                    cjkFonts = new Properties();
                    cjkEncodings = new Properties();
                }

                propertiesLoaded = true;
            }
        }
    }
}

CJKFont会先加载com/lowagie/text/pdf/fonts下的并不存在的cjkfonts.properties和cjkencodings.properties文件，然后再获取var0(即"STSong-Light")的值为null，所以isCJKFont方法返回false
再回上面查看代码可知，直接抛出异常

com.itextpdf.text.pdf.BaseFont

下面我们看一下com.itextpdf.text.pdf.BaseFont的源码

public static BaseFont createFont(String name, String encoding, boolean embedded, boolean cached, byte[] ttfAfm, byte[] pfb, boolean noThrow, boolean forceRead) throws DocumentException, IOException {
	String nameBase = getBaseName(name);//nameBase值为"S"
	encoding = normalizeEncoding(encoding);
	//isBuiltinFonts14=false
	boolean isBuiltinFonts14 = BuiltinFonts14.containsKey(name);//看这里
	//isCJKFont=true
	boolean isCJKFont = isBuiltinFonts14 ? false : CJKFont.isCJKFont(nameBase, encoding);//看这里
	if (!isBuiltinFonts14 && !isCJKFont) {
	    if (encoding.equals("Identity-H") || encoding.equals("Identity-V")) {
	        embedded = true;
	    }
	} else {
	    embedded = false;
	}
	....
	if (!isBuiltinFonts14 && !name.toLowerCase().endsWith(".afm") && !name.toLowerCase().endsWith(".pfm")) {
        if (!nameBase.toLowerCase().endsWith(".ttf") && !nameBase.toLowerCase().endsWith(".otf") && nameBase.toLowerCase().indexOf(".ttc,") <= 0) {
            if (!isCJKFont) {//isCJKFont=true
                if (noThrow) {
                    return null;
                }
                throw new DocumentException(MessageLocalization.getComposedMessage("font.1.with.2.is.not.recognized", new Object[]{name, encoding}));
            }
            fontBuilt = new CJKFont(name, encoding, embedded);//返回结果值
            ....
    ....
    return (BaseFont)fontBuilt;
}

BuiltinFonts14.containsKey(name);与com.lowagie.text.pdf.BaseFont中逻辑相同，这里不再讲述了。

public static boolean isCJKFont(String fontName, String enc) {
    loadProperties();//看这里
    if (!registryNames.containsKey("fonts")) {
        return false;
    } else if (!((Set)registryNames.get("fonts")).contains(fontName)) {
        return false;
    } else if (!enc.equals("Identity-H") && !enc.equals("Identity-V")) {
        String registry = (String)((HashMap)allFonts.get(fontName)).get("Registry");
        Set encodings = (Set)registryNames.get(registry);
        return encodings != null && encodings.contains(enc);
    } else {
        return true;
    }
}

private static void loadProperties() {
    if (!propertiesLoaded) {
        HashMap var0 = allFonts;
        synchronized(allFonts) {
            if (!propertiesLoaded) {
                try {
                    loadRegistry();//看这里
                    Iterator i$ = ((Set)registryNames.get("fonts")).iterator();

                    while(i$.hasNext()) {
                        String font = (String)i$.next();
                        allFonts.put(font, readFontProperties(font));
                    }
                } catch (Exception var4) {
                    ;
                }

                propertiesLoaded = true;
            }
        }
    }
}

private static void loadRegistry() throws IOException {
    //加载cjk_registry.properties文件
    InputStream is = StreamUtil.getResourceStream("com/itextpdf/text/pdf/fonts/cmaps/cjk_registry.properties");
    Properties p = new Properties();
    p.load(is);
    is.close();
    Iterator i$ = p.keySet().iterator();

    while(i$.hasNext()) {
        Object key = i$.next();
        String value = p.getProperty((String)key);
        String[] sp = value.split(" ");
        Set hs = new HashSet();
        String[] arr$ = sp;
        int len$ = sp.length;

        for(int i$ = 0; i$ < len$; ++i$) {
            String s = arr$[i$];
            if (s.length() > 0) {
                hs.add(s);
            }
        }

        registryNames.put((String)key, hs);
    }

}

cjk_registry.properties如下

Adobe_Japan1=78-EUC-H 78-EUC-V 78-H 78-RKSJ-H 78-RKSJ-V 78-V 78ms-RKSJ-H 78ms-RKSJ-V 83pv-RKSJ-H 90ms-RKSJ-H 90ms-RKSJ-V 90msp-RKSJ-H 90msp-RKSJ-V 90pv-RKSJ-H 90pv-RKSJ-V Add-H Add-RKSJ-H Add-RKSJ-V Add-V Adobe-Japan1-0 Adobe-Japan1-1 Adobe-Japan1-2 Adobe-Japan1-3 Adobe-Japan1-4 Adobe-Japan1-5 Adobe-Japan1-6 EUC-H EUC-V Ext-H Ext-RKSJ-H Ext-RKSJ-V Ext-V H Hankaku Hiragana Katakana NWP-H NWP-V RKSJ-H RKSJ-V Roman UniJIS-UCS2-H UniJIS-UCS2-HW-H UniJIS-UCS2-HW-V UniJIS-UCS2-V UniJIS-UTF16-H UniJIS-UTF16-V UniJIS-UTF32-H UniJIS-UTF32-V UniJIS-UTF8-H UniJIS-UTF8-V UniJIS2004-UTF16-H UniJIS2004-UTF16-V UniJIS2004-UTF32-H UniJIS2004-UTF32-V UniJIS2004-UTF8-H UniJIS2004-UTF8-V UniJISPro-UCS2-HW-V UniJISPro-UCS2-V UniJISPro-UTF8-V UniJISX0213-UTF32-H UniJISX0213-UTF32-V UniJISX02132004-UTF32-H UniJISX02132004-UTF32-V V WP-Symbol
Adobe_Korea1=Adobe-Korea1-0 Adobe-Korea1-1 Adobe-Korea1-2 KSC-EUC-H KSC-EUC-V KSC-H KSC-Johab-H KSC-Johab-V KSC-V KSCms-UHC-H KSCms-UHC-HW-H KSCms-UHC-HW-V KSCms-UHC-V KSCpc-EUC-H KSCpc-EUC-V UniKS-UCS2-H UniKS-UCS2-V UniKS-UTF16-H UniKS-UTF16-V UniKS-UTF32-H UniKS-UTF32-V UniKS-UTF8-H UniKS-UTF8-V
Adobe_GB1=Adobe-GB1-0 Adobe-GB1-1 Adobe-GB1-2 Adobe-GB1-3 Adobe-GB1-4 Adobe-GB1-5 GB-EUC-H GB-EUC-V GB-H GB-V GBK-EUC-H GBK-EUC-V GBK2K-H GBK2K-V GBKp-EUC-H GBKp-EUC-V GBpc-EUC-H GBpc-EUC-V GBT-EUC-H GBT-EUC-V GBT-H GBT-V GBTpc-EUC-H GBTpc-EUC-V UniGB-UCS2-H UniGB-UCS2-V UniGB-UTF16-H UniGB-UTF16-V UniGB-UTF32-H UniGB-UTF32-V UniGB-UTF8-H UniGB-UTF8-V
Adobe_CNS1=Adobe-CNS1-0 Adobe-CNS1-1 Adobe-CNS1-2 Adobe-CNS1-3 Adobe-CNS1-4 Adobe-CNS1-5 Adobe-CNS1-6 B5-H B5-V B5pc-H B5pc-V CNS-EUC-H CNS-EUC-V CNS1-H CNS1-V CNS2-H CNS2-V ETen-B5-H ETen-B5-V ETenms-B5-H ETenms-B5-V ETHK-B5-H ETHK-B5-V HKdla-B5-H HKdla-B5-V HKdlb-B5-H HKdlb-B5-V HKgccs-B5-H HKgccs-B5-V HKm314-B5-H HKm314-B5-V HKm471-B5-H HKm471-B5-V HKscs-B5-H HKscs-B5-V UniCNS-UCS2-H UniCNS-UCS2-V UniCNS-UTF16-H UniCNS-UTF16-V UniCNS-UTF32-H UniCNS-UTF32-V UniCNS-UTF8-H UniCNS-UTF8-V
Adobe_Japan1_Uni=UniJIS-UTF16-H UniJIS-UTF16-V
Adobe_Korea1_Uni=UniKS-UTF16-H UniKS-UTF16-V
Adobe_GB1_Uni=UniGB-UTF16-H UniGB-UTF16-V
Adobe_CNS1_Uni=UniCNS-UTF16-H UniCNS-UTF16-V
fonts=HeiseiMin-W3 HeiseiKakuGo-W5 KozMinPro-Regular STSong-Light STSongStd-Light MHei-Medium MSung-Light MSungStd-Light HYGoThic-Medium HYSMyeongJo-Medium HYSMyeongJoStd-Medium

OK，到此为止，通过查看源码可知com.lowagie.text.pdf.BaseFont去加载不存在的文件而获取不到"STSong-Light"和"UniGB-UCS2-H"配置值而抛出异常；
而com.itextpdf.text.pdf.BaseFont返回的结果为
(BaseFont)new CJKFont(name, encoding, embedded);
时间紧迫，文笔不好。-_-