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http断点续传简单实现(java)

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/* [J|)DUjt  
**SiteFileFetch.java JL4\%  
*/ lll]FJ1  
package NetFox; +89s+4Jn  
import java.io.*; bt,^-gt@  
import java.net.*; &ns !\!  
#D$vH  
*|RQ )  
public class SiteFileFetch extends Thread { )k8=< =s  
*kXSl73 k  
A qKl}8  
SiteInfoBean siteInfoBean = null; //文件信息Bean GP5Y5 )  
long[] nStartPos; //开始位置 pCQB<6&1N  
long[] nEndPos; //结束位置 ;y7V-sf  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _Z|s!~wdz  
long nFileLength; //文件长度 PL#8~e;'  
boolean bFirst = true; //是否第一次取文件 i~dW)7  
boolean bStop = false; //停止标志 ''Y}Q"  
File tmpFile; //文件下载的临时信息 ?5#Ng,8iT  
DataOutputStream output; //输出到文件的输出流 yuvt<kz  
;u'mSJI'  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) tZ]|3wp  
public SiteFileFetch(SiteInfoBean bean) throws IOException >Udb*76 D  
{ ~R]E=/m|  
siteInfoBean = bean; Ne<"o]_M  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); DGx9 \8^  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); kN4nRW9z  
if(tmpFile.exists ()) 6s833Tmb&r  
{ 7R mL#f`  
bFirst = false; :4"SJ  
read_nPos(); +b.qzgH>r  
} _$me.  
else }*~EA=YN;  
{ )K8k3]y&  
nStartPos = new long[bean.getNSplitter()]; 5O Ob(  
nEndPos = new long[bean.getNSplitter()]; s7C oUd2  
} \]U@=w  
zn T85#]\@  
U n#7@8,  
66?!"w  
} mAFqA  
,uD F#xjl,  
2roPZj  
public void run() x+vNA J  
{ h94SLj]  
//获得文件长度 ~ySmN}3~'  
//分割文件 EdA_Hf  
//实例FileSplitterFetch #dDsI]E )  
//启动FileSplitterFetch线程 fv !l{  
//等待子线程返回 ujZki.x  
try{ 6y,M+{  
if(bFirst) :z%vNKy1  
{ ]],6Fi+  
nFileLength = getFileSize(); >eg&i(C+  
if(nFileLength == -1) sQ/7Mc  
{ n*^g^gp  
System.err.println("File Length is not known!"); ei;wT  
} zYdSg<[^  
else if(nFileLength == -2) ~F*pV*  
{ h'<}N  
System.err.println("File is not access!"); F_!6C-z  
} GV1\8OG7  
else ~1pJQ)!zlq  
{ @5H1Ni5/o@  
for(int i=0;i<nStartPos.length;i++) o$m64l  
{ PNXZ3:W  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); L`YnrDZK  
} .Lo$uKsW$l  
for(int i=0;i<nEndPos.length-1;i++) I]>-~_  
{ YH^_d3A;  
nEndPos = nStartPos[i+1]; 4@|K^nT`  
} -vI?b#  
nEndPos[nEndPos.length-1] = nFileLength; $=$I^hV  
} Z9ciS";L  
} v@;:aN  
PGMu6$  
C8cB Lsa[J  
//启动子线程 D5)qmu  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;h_"5/#  
for(int i=0;i<nStartPos.length;i++) mSAuS)YD  
{ 8Uvf9,I'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #6_?7 (X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MC/$:PV  
nStartPos,nEndPos,i); sMli!u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y-}lz#N  
fileSplitterFetch.start(); 2GcQh]ohc  
} YL&$cT]1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), it\{#rb=4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a=k+:=%y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XZuJ<]}X,  
nEndPos = " + nFileLength); a=gTGG"9  
// fileSplitterFetch[nPos.length-1].start(); &Z5$ 5,[  
0G9@A8LU  
Giz9jzF \  
//等待子线程结束 *#Hi W)  
//int count = 0; ]c+qD,wqt>  
//是否结束while循环 <"/Y`/  
boolean breakWhile = false; E8=.TM]L  
%p"x|e  
A$A7 F=x  
while(!bStop) oo3ZYA  
{ x2/|i? ZO  
write_nPos(); jDcE_55o  
Utility.sleep(500); ;=hl!CB  
breakWhile = true; N{iBVl  
7*OO k"9  
5JDqSz{  
for(int i=0;i<nStartPos.length;i++) =ALy.^J=  
{ ][:6En}  
if(!fileSplitterFetch.bDownOver) _x z_D12  
{ E3.=|]W'  
breakWhile = false; }f^r@3Cb3  
break; eGvHU ;@  
} QY-P!JD  
} >Fz_]z   
if(breakWhile) NaG1j+LN  
break; ZP*Hx %U  
v*QobI  
z]Z>+|  
//count++; 1QE-[|  
//if(count>4) l},*^Sn<5  
// siteStop(); dnNC = siY  
} d#I'9O0&  
B[C2uVEX:  
zrU0YHmt  
System.err.println("文件下载结束!"); q+dY&4&u  
} 6,uW{l8L  
catch(Exception e){e.printStackTrace ();} s[h'W~  
} }@4m@_gR?  
}0?642 =-  
j)C%zzBu(  
//获得文件长度 <|Bh;;  
public long getFileSize() O9A.WSJ >}  
{ }{:H0)H*  
int nFileLength = -1; f&H):.  
try{ X~5TA)h;~  
URL url = new URL(siteInfoBean.getSSiteURL()); m}]"TFzoVM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h -+vM9j  
httpConnection.setRequestProperty("User-Agent","NetFox"); !zvKl;yT  
;_of'  
waQNX7Xdn  
int responseCode=httpConnection.getResponseCode(); }Nl-3I.S^  
if(responseCode>=400) E92dSLhs5  
{ +kH*BhSj  
processErrorCode(responseCode); ;QW6Tgt11  
return -2; //-2 represent access is error qUx!-DMY  
} ep3_G\m  
N|z-s  
joAR;J  
String sHeader; eek5Xm  
>6=yxCJ  
fa/ '4  
for(int i=1;;i++) WY?(C@>s  
{ D._q'v<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8G1Tpn  
//Utility.log(in.readLine()); K`j#'`/KC  
sHeader=httpConnection.getHeaderFieldKey(i); Yj/S(4(h?  
if(sHeader!=null) #_QvnQ?I  
{ KZ`d3ad  
if(sHeader.equals("Content-Length")) {_ww1'|A  
{ EHcqj;@m  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]$4k+)6  
break; %K;,qS'N_  
} aIRCz=N  
} * ?rw'  
else b,~4O~z  
break; ToCB*GlL  
} wP6~HiC  
} $oH?oD1  
catch(IOException e){e.printStackTrace ();} bh6Mh< +  
catch(Exception e){e.printStackTrace ();} g/mVd;#o  
Up*p*(d3  
q3VE\&*^F  
Utility.log(nFileLength); OlRBv foh8  
7cr+a4T33  
T}$1<^NK  
return nFileLength; tKo ^A:M  
} @GBS-iT3  
C "<l}  
4.|]R8Mn  
//保存下载信息(文件指针位置) I`t"Na2i  
private void write_nPos() [O&2!x  
{ pxM^|?Hxc  
try{ "|]'\4UdzQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2!-ZNd:(+  
output.writeInt(nStartPos.length); |5Mhrb4.  
for(int i=0;i<nStartPos.length;i++) 3:Y ZC9  
{ R8c1~'  
// output.writeLong(nPos); :v* _Ay  
output.writeLong(fileSplitterFetch.nStartPos); Ol~sCr  
output.writeLong(fileSplitterFetch.nEndPos); vE>J@g2#  
} +Ys<V  
output.close(); ?c+_}ja,  
} /wKW  
catch(IOException e){e.printStackTrace ();} Aw;~b&.U{_  
catch(Exception e){e.printStackTrace ();} gZM\RJZ_  
} S M@l4GH  
x5WFPY$wM  
I6M 7xn  
//读取保存的下载信息(文件指针位置) GW ?.b_6*  
private void read_nPos() *["9;_KD  
{ 3K@dW"3  
try{ UVUbxFq:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !Jh-v  
int nCount = input.readInt(); G>M# BuU  
nStartPos = new long[nCount]; Vu*yEF}  
nEndPos = new long[nCount]; &AU%3b  
for(int i=0;i<nStartPos.length;i++) ` *&*jdq&i  
{ PnFU{N  
nStartPos = input.readLong(); Nw+0b4{  
nEndPos = input.readLong(); S?D|"#-,  
} pez[qs  
input.close(); 6U @3 xU`  
} zKx?cEpE  
catch(IOException e){e.printStackTrace ();} kmi[u8iXD_  
catch(Exception e){e.printStackTrace ();} (VO) Q  
} w_ kHy_)  
IwZn%>1N  
e/6WhFN #  
private void processErrorCode(int nErrorCode) @rRBo:0%  
{ ]sd|u[:k  
System.err.println("Error Code : " + nErrorCode); d?oupW}uu  
} 1 C{n!l  
ivb&J4?y  
2rB$&>}T  
//停止文件下载 gLsl/G  
public void siteStop() zg.'  
{ Kg VLXI6  
bStop = true; oA(jtX[(  
for(int i=0;i<nStartPos.length;i++) c;xL.  
fileSplitterFetch.splitterStop(); Tt `|26/  
x4CrWm  
J*-m!0 5  
} L oe!@c  
} o*_[3{FU  
//负责部分文件的抓取 ^ W eE%"  
**FileSplitterFetch.java al F*L  
*/ f+}? $'  
package NetFox; 6;dQ#wmg  
`l9Pk\X[  
s_hf,QH  
import java.io.*; 0F8y8s  
import java.net.*; }W#Gf.$6C  
kUUN2  
E b-?wzh  
public class FileSplitterFetch extends Thread { MG*#-<OV.  
^+F@KXn L  
we4e>)  
String sURL; //File URL Sqed*  
long nStartPos; //File Snippet Start Position Lp 5LRw  
long nEndPos; //File Snippet End Position >to NGGU=~  
int nThreadID; //Thread's ID [<}:b>a  
boolean bDownOver = false; //Downing is over :UoZ`O~  
boolean bStop = false; //Stop identical vDV` !JU  
FileAccessI fileAccessI = null; //File Access interface }N]|zCEj  
G!RbM.6  
:@y!5[88!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Fx0E4\-  
{ M n`gd#  
this.sURL = sURL; MRxzOs  
this.nStartPos = nStart; sTP`xaY  
this.nEndPos = nEnd; >2x[ub%$L  
nThreadID = id; Gw:8-bxS  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7"yA~e,l  
} skh6L!6*<  
a9j f7r1  
w=vK{h#8  
public void run() ?[hIv6c  
{ +;c)GNQ)6:  
while(nStartPos < nEndPos && !bStop) H{VVxj  
{ .}&bE1  
w= |).qQ]  
hD/bgquT  
try{ -%E+Yl{v  
URL url = new URL(sURL); y))d[ 1E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0UB)FK ,9  
httpConnection.setRequestProperty("User-Agent","NetFox"); %"r3{Hs  
String sProperty = "bytes="+nStartPos+"-"; z4!TK ps  
httpConnection.setRequestProperty("RANGE",sProperty); ?x7zYE,6  
Utility.log(sProperty); =H%c/Jty  
o9(:m   
'`p#%I@  
InputStream input = httpConnection.getInputStream(); x9bfH1  
//logResponseHead(httpConnection); St7ZyN1  
$ jWe!]ASU  
8)\Td tBf9  
byte[] b = new byte[1024]; *v 1hMk  
int nRead; u27K 0}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O68/Hf1W  
{ ,j>A[e&.  
nStartPos += fileAccessI.write(b,0,nRead); 3.Z}2F]  
//if(nThreadID == 1) @d:TAwOI'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #!wu}nDu  
} qPDe;$J)  
}enm#0Ha  
PN:/lIO  
Utility.log("Thread " + nThreadID + " is over!"); H:Y?("k  
bDownOver = true; @W[`^jfQ  
//nPos = fileAccessI.write (b,0,nRead); f]W$4f {  
} |=fa`8m G  
catch(Exception e){e.printStackTrace ();} _CN5,mLNRk  
} 15U]/?jv8  
} ZX[ @P?A+-  
/Fy2ZYs,`8  
b-ZC~#?|b  
//打印回应的头信息 ^&F8NEb=2>  
public void logResponseHead(HttpURLConnection con) h)fJ2]JW8W  
{ fQ33J>  
for(int i=1;;i++) `n7*6l<k~4  
{ .xo#rt9_"=  
String header=con.getHeaderFieldKey(i); LfOXgn\  
if(header!=null) B*!{LjXV  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o9& 1Ct  
Utility.log(header+" : "+con.getHeaderField(header)); hC2@Gq  
else ! eXDN  
break; L lOUK2tZ  
} 8MqKS}\H  
} D@A@5pvS  
`1k0wT(  
, 7-@eZ  
public void splitterStop() r#hA kOw  
{ OZ##x  
bStop = true; ,'w9@A  
} %ub\+~  
f|Dq#(^\  
HjCcfOej  
} p?F%a;V3  
t M?3oO  
:j feY  
/* _]zm02|  
**FileAccess.java z0|%h?N  
*//文件访问(定位,写) 'b(V8x  
package NetFox; KYBoGCS>  
import java.io.*; FbO\#p s  
h[H FZv~{  
_voU^-  
public class FileAccessI implements Serializable{ 21ng94mC  
0 ~K4vSa  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |uL"/cMW7  
RandomAccessFile oSavedFile; :+Ti^FF`w  
long nPos; r0jhIE#  
 {}x{OP  
~Y;_vU  
public FileAccessI() throws IOException "A?&`}%  
{ K6 D3  
this("",0); 86+nFk  
} qcpAjjK  
a2Q_K2t  
4FLL*LCNX  
public FileAccessI(String sName,long nPos) throws IOException (NB\wJg $  
{ G_OLUuK?C  
oSavedFile = new RandomAccessFile(sName,"rw"); (.[HE ~ s?  
this.nPos = nPos; U&x)Q  
oSavedFile.seek(nPos); ^q{=mf`  
} KlOL5"3  
Sy\ec{$+V]  
o& -c5X4  
public synchronized int write(byte[] b,int nStart,int nLen) =XAFW  
{ HYqDaRn  
int n = -1; lO)-QE+  
try{ 3hUU$|^4gm  
oSavedFile.write(b,nStart,nLen); ]H[%PQ r`Z  
n = nLen; :x*#RnRr.  
} U42B( ow  
catch(IOException e) eD<Kk 4){  
{ -bJC+Yn  
e.printStackTrace (); \M(#FS  
} Q--Hf$D]H  
iH&BhbRu_  
.MUoNk!  
return n; ..u2IdEu  
} gFBMARxi  
7Qoy~=E  
 a@mMa {  
} 3/d`s0O  
$K-od3h4=  
r*Iu6  
/* g+ZQ6Hz  
**SiteInfoBean.java 4\Nt"#U)g  
*/ h4N%(?7  
package NetFox; Pgdv)i3  
BZUA/;Hz &  
&n 1 \^:  
public class SiteInfoBean { $)(K7> P  
ItLP&S=  
LA\)B"{J  
private String sSiteURL; //Site's URL fwWE`BB  
private String sFilePath; //Saved File's Path j)A$%xUo  
private String sFileName; //Saved File's Name v J `'x  
private int nSplitter; //Count of Splited Downloading File b!do7%]i  
`y%1K|Y=  
fQ.{s Q$@h  
public SiteInfoBean() cx_.+R  
{//nSplitter的缺省值为5 aNcuT,=(?8  
//default value of nSplitter is 5 estDW1i)  
this("","","",5); Qx{[#[Da  
} (=de#wh2]  
w26x)(7  
v8PH(d2{@  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~4MUac^w  
{ Vy+UOV&v-  
sSiteURL= sURL; zLeId83>  
sFilePath = sPath; (K"8kQLY  
sFileName = sName; DnY7$']"|  
this.nSplitter = nSpiltter; BkO)hze  
-( d,AX  
M?yWFqFt9m  
} ? FlV<nE"J  
h_w_OCC&2  
zc,kHO|  
public String getSSiteURL() T d6Gu"  
{ gp?|UMA9 .  
return sSiteURL; _mi(:s(  
} Xfq]vQ/{  
]n/fB|tE  
l>H G|ol  
public void setSSiteURL(String value) 4t Z. T9d  
{ Wd0$t    
sSiteURL = value; #!h +K"wX  
} Y64B"J=P 9  
x?|C-v  
P0/B!8x  
public String getSFilePath() *, Mg  
{ Xy;!Q`h(  
return sFilePath; Z T5p  
} NbDfD3 1GK  
G0u3*.  
s</llJ$  
public void setSFilePath(String value) -_>g=a@&  
{ Qey6E9eCA  
sFilePath = value; DJm/:td  
} t G{?  
x: Nd>Fb  
WecJ^{g>r{  
public String getSFileName() *C0gpEf9S  
{ CYxrKW l:'  
return sFileName; SdI/  
} 7+h*&f3>  
wn$:L9"YN  
4-YXXi}  
public void setSFileName(String value) c= -2c&=&  
{ q|8p4X}/]  
sFileName = value; "eH~/6A  
} c/c%-=  
te+5@k#t  
CCX!>k]  
public int getNSplitter() a%wK[yVp  
{ {]a 6o[}u  
return nSplitter; h0N*hx   
} jJ' LM>e  
? 77ye  
M~G1ZB  
public void setNSplitter(int nCount) SwDUg}M~  
{ {mlJE>~%  
nSplitter = nCount; i>M*ubWE4@  
} ? }k~>. \  
} 7 -(LWH  
YS_9M Pi  
<IF\;,.c  
/* jZ'y_  
**Utility.java <N{pMz  
*/ iZ`1Dzxgk  
package NetFox; us.+nnd  
N1V qK  
|sw&sfH[FD  
public class Utility { AR}M*sSh  
`B`/8Cvg  
:*2+t-  
public Utility() l; e&p${P  
{ lRn6Zh  
v!;E1  
t `4^cd5V  
} d E@R7yU@  
9iQcK&D 2  
//线程睡眠 RfT#kh/5  
public static void sleep(int nSecond) h&!k!Su3#  
{ "~h.u  
try{ V.IgEE]  
Thread.sleep(nSecond); ,x+_/kqx  
} ax0:v!,e  
catch(Exception e) |U_48  
{ y\ nR0m  
e.printStackTrace (); C { }s  
} 4*UoTE-g$  
} ifu "e_^  
l|-TGjsX  
//日志  X7sWu{n  
public static void log(String sMsg) tPS.r.0#^  
{ MwxfTH"wi  
System.err.println(sMsg); z]k=sk  
} Ne]/ sQ0  
{-rK:*yP'u  
-=E/_c;  
public static void log(int sMsg) yG0Wr=/<?  
{ .P=uR8  
System.err.println(sMsg); ?lxI& h  
} eiZv|?^0  
} auP:r  
i3.8m=>  
[Cz.K?+#M  
/* ~Exd_c9  
**TestMethod.java 1Tn!.E *  
*/ E<3hy  
package NetFox; 3zb;q@JV  
y+RT[*bX5o  
VI%879Z\e  
public class TestMethod { /Q"nQSG  
s)HbBt-  
o'Q)V  
public TestMethod() ^zGgvFf>  
{ ///xx/weblogic60b2_win.exe  "7!K'i  
try{ |}*k|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %E7+W{?*1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )o[ O%b  
SiteFileFetch fileFetch = new SiteFileFetch(bean); h<*l=`#  
fileFetch.start(); xZ@H{):  
} f8! PeQ?  
catch(Exception e){e.printStackTrace ();} @A6\v+ih  
&Ko}Pv  
1fL@rR  
} FTt7o'U  
DR9M8E  
M[_~7~4  
public static void main(String[] args) xIF z@9+k  
{ RlX;c!K  
new TestMethod(); GI$t8{M  
} ',0~\V  
} vjJ!d#8  
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