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http断点续传简单实现(java)

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/* [C#H _y(  
**SiteFileFetch.java 29HyeLB@  
*/ OWys`2W  
package NetFox; 'NNfzh  
import java.io.*; Et! 6i7`]  
import java.net.*; OQ&'3hv{  
Kh8  
@tIY%;Bgk  
public class SiteFileFetch extends Thread { 2C Fgit  
V7"^.W*  
F{G.dXZZ<  
SiteInfoBean siteInfoBean = null; //文件信息Bean /UqIkc  
long[] nStartPos; //开始位置 4KX\'K  
long[] nEndPos; //结束位置 %Ze]6TP/><  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 w{WEYS  
long nFileLength; //文件长度 ,hOi5,|?L  
boolean bFirst = true; //是否第一次取文件 ElA(1o|9I  
boolean bStop = false; //停止标志 9vckQCLM  
File tmpFile; //文件下载的临时信息 g)1`A 24  
DataOutputStream output; //输出到文件的输出流 sj3[ny;b  
yBRYEqS+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) h0&Oy52  
public SiteFileFetch(SiteInfoBean bean) throws IOException ._q}lWT  
{ C"QB`f:  
siteInfoBean = bean; onU\[VvM  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); l4> c  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6)veuA3]  
if(tmpFile.exists ()) /E-s g, k  
{ &0`i(l4]l  
bFirst = false; #OlPnP2  
read_nPos(); "s.hO0Z  
} [Y4Wm?  
else Z,oCkv("n  
{ I8/tD|3  
nStartPos = new long[bean.getNSplitter()]; c2u*<x  
nEndPos = new long[bean.getNSplitter()]; {G+iobQdd  
} 9S|a!9J  
[]$L"?]0uk  
 u]OYu  
+~V)&6Vn  
} IuY4R0Go  
&^7(?C' u  
Qd/x{a8  
public void run() 4" pU\g  
{ w! PguP  
//获得文件长度 !;UoZ~  
//分割文件 t,u;"%go  
//实例FileSplitterFetch Kk).KgR  
//启动FileSplitterFetch线程 =gB8(1g8  
//等待子线程返回 >9NC2%61S  
try{ "&/lF[q  
if(bFirst) @A|#/]S1  
{ &~c`p[  
nFileLength = getFileSize(); <1#hX(Q  
if(nFileLength == -1) 81H9d6hqcD  
{ S%j W} v';  
System.err.println("File Length is not known!"); X"sJiFS  
} H*P[tyz$  
else if(nFileLength == -2) {DapXx  
{ q8!]x-5$6j  
System.err.println("File is not access!"); `pjB^--w  
} p<<dj%  
else #;= sJ[m4  
{ Tol"D2cyf  
for(int i=0;i<nStartPos.length;i++) X/_89<&  
{ &xpvHKJl  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,n2"N5{jw  
} "A> _U<Y  
for(int i=0;i<nEndPos.length-1;i++) \ B'AXv 6  
{ G +&pq  
nEndPos = nStartPos[i+1]; e$Mvl=NYp\  
}  \EXa 9X2  
nEndPos[nEndPos.length-1] = nFileLength; qLPuKIF  
} V%B~ q`4  
} -Iis/Xw:  
y\ })C-&  
gT(8.<h8  
//启动子线程 -Jf}3$Ra  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1aZGt2;  
for(int i=0;i<nStartPos.length;i++) D"2bgw  
{ w"37sv  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H>Ucmd;ay  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dUUg}/  
nStartPos,nEndPos,i); ' &3,qT  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wD:2sri  
fileSplitterFetch.start(); :cf#Tpq"  
} r@}8TE*|P  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FU(2,Vl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gLRDd~H  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Omi/sKFMi  
nEndPos = " + nFileLength); I9dX\w}  
// fileSplitterFetch[nPos.length-1].start(); =ym<yI<  
vOLa.%X]h  
5,4m_fBoW  
//等待子线程结束 {9@u:(<X9  
//int count = 0; <xe_t=N  
//是否结束while循环 Cg|\UKfy$  
boolean breakWhile = false; LIrebz  
0 6M?ecN  
JL>frS3M  
while(!bStop) ddN G :  
{ :>/6:c?atG  
write_nPos(); CYlS8j  
Utility.sleep(500); LJom+PxF$x  
breakWhile = true; *<[zG7+&[  
)TEm1\  
/::Y &&$f  
for(int i=0;i<nStartPos.length;i++) 4U16'd  
{ WEJ-K<A(  
if(!fileSplitterFetch.bDownOver) !iq|sXs  
{ #G_'5{V  
breakWhile = false; T|0+o+i  
break; 8.>himL  
} ]G D` f  
} \ @[Q3.VX  
if(breakWhile) |fW_9={1kQ  
break; kv6nVlI)B  
.wmqaLd%  
&YcOmI/MM  
//count++; N:okt)q:%  
//if(count>4) cRuN;  
// siteStop(); zWv0y8[d  
} yn"4qC#Z  
J .VZD  
O;5lF  
System.err.println("文件下载结束!"); ?;H}5>^8P  
} Pjn{3/*wi  
catch(Exception e){e.printStackTrace ();} j@w1S[vt  
} ,<'>j a C  
Br15S};Ce  
z{FFTb^B  
//获得文件长度 2Y<]X7Ch:  
public long getFileSize() FE]UqB  
{ )0]U"Nf ho  
int nFileLength = -1; 1D3 8T  
try{ Dx`-h#  
URL url = new URL(siteInfoBean.getSSiteURL()); 0AdxV?6z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fi;H   
httpConnection.setRequestProperty("User-Agent","NetFox"); ^8A [ ^cgq  
!%D';wQ,/  
vj 344B  
int responseCode=httpConnection.getResponseCode(); VX82n,'=t  
if(responseCode>=400) TVx `&C+  
{ I{r*Y9  
processErrorCode(responseCode); N>,`TsUwW  
return -2; //-2 represent access is error _Gf-s51s  
} M0~%[nX  
!_QT{H  
F>3 o0ke}  
String sHeader; k& +gkJm  
E1tCY.N{  
dq`{fqGl  
for(int i=1;;i++) k].swvIi  
{ D7T|K :F)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E>f{j:M  
//Utility.log(in.readLine()); *coUHbP9>  
sHeader=httpConnection.getHeaderFieldKey(i); AWYlhH4c?t  
if(sHeader!=null) G}^=(,jl  
{ P"l'? `  
if(sHeader.equals("Content-Length")) 1+WVh7gF  
{ i>]PW|]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `}KxzD  
break; 1kw*Q:   
} )dqNN tS  
} 0 p ?AL=  
else fK+ 5   
break; pjX=:K|  
} Eu:/U*j  
} C}pm>(F~  
catch(IOException e){e.printStackTrace ();} ZJQFn  
catch(Exception e){e.printStackTrace ();} 1}c'UEr%)  
gwQMy$  
iB"ji4[z  
Utility.log(nFileLength); )\ceanS  
7=9>yba)^  
Su"Z3gm5Kw  
return nFileLength; 9Dgs A`{$  
} Ul9^"o  
K%+4M#jj5  
Q}OloA(+  
//保存下载信息(文件指针位置) op5 `#{  
private void write_nPos() 8cG`We8l&  
{ q(:L8nKT]  
try{ ~F@n `!c  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .pQ5lK(R  
output.writeInt(nStartPos.length); cS7\,/4S  
for(int i=0;i<nStartPos.length;i++) kj[box N  
{ _1qR1< V  
// output.writeLong(nPos); 3MFT P5~  
output.writeLong(fileSplitterFetch.nStartPos); @R50M (@W  
output.writeLong(fileSplitterFetch.nEndPos); !?0C(VL(:  
} ;'8Wl  
output.close(); N+B!AK0.  
} 'JJKnE zQ  
catch(IOException e){e.printStackTrace ();} ~{tO8 ]  
catch(Exception e){e.printStackTrace ();} |xcC'1WU  
} Qd kus 214  
QfAmGDaYQ  
v9-4yZU^WR  
//读取保存的下载信息(文件指针位置)  IPK1g3Z  
private void read_nPos() xh$yXP0/  
{ vm_]X{80;  
try{ t_w\k_ T  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -43>?m/a  
int nCount = input.readInt(); B I)@n:p  
nStartPos = new long[nCount]; U364'O8_  
nEndPos = new long[nCount]; m^!j)\sM5  
for(int i=0;i<nStartPos.length;i++) T@U,<[,   
{ BJWlx*U]  
nStartPos = input.readLong(); }7 +%k/  
nEndPos = input.readLong(); /go[}X5QR[  
} qe{;EH*  
input.close(); 8I RKCuV  
} Q|h$D~  
catch(IOException e){e.printStackTrace ();} zpT^:Ag  
catch(Exception e){e.printStackTrace ();} n19A>,m  
} GHd1?$  
^ExuIe  
$V!.z%Vgf  
private void processErrorCode(int nErrorCode) XV]xym~  
{ 8+}rm6Y+  
System.err.println("Error Code : " + nErrorCode); <3BGW?=WP  
} \WFcb\..  
XZARy:+bc  
bRy(`  
//停止文件下载 q%])dZ!lE  
public void siteStop() #<b\BqYG  
{ 5)T[ha77u  
bStop = true; [;Lgbgt3f  
for(int i=0;i<nStartPos.length;i++) V<S6 a  
fileSplitterFetch.splitterStop(); G&^8)S@1  
<i</pA  
!>> A@3  
} 3= sBe HL  
} (~N?kh:  
//负责部分文件的抓取 S,6/X.QBv  
**FileSplitterFetch.java Y Z+G7D>  
*/ AZc= Bbh  
package NetFox; trwQ@7  
EA>.SSs!  
>9A18xC  
import java.io.*; C{85#`z`  
import java.net.*; G`O*AQ}[  
rP7 QW)NF  
>P~*@>e  
public class FileSplitterFetch extends Thread { *{#C;"  
0H>gMXWE]  
zu{K"7Bx  
String sURL; //File URL 1gkpK`u(B  
long nStartPos; //File Snippet Start Position 1m"WrTen  
long nEndPos; //File Snippet End Position g{6jN  
int nThreadID; //Thread's ID (JlPe)Q5  
boolean bDownOver = false; //Downing is over ]VKQm(,0  
boolean bStop = false; //Stop identical Ut\:jV=f  
FileAccessI fileAccessI = null; //File Access interface Gm:s;w-;v  
U52 V1b  
z~vcwiYAP  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GWuKDq  
{  FNH)wk  
this.sURL = sURL; nL=+`aq_  
this.nStartPos = nStart; Yft [)id  
this.nEndPos = nEnd;  d=^QK{8  
nThreadID = id; Pb?vi<ug+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :FI D ,  
} ao9#E"BfM  
Eej Lso#\  
]#f%Dku.m  
public void run() lL:!d.{  
{ 4E5;wH  
while(nStartPos < nEndPos && !bStop) Rk g8  
{ NJsaTBT  
@a@}xgn{  
_xCYh|DlQ|  
try{ a($7J6]M  
URL url = new URL(sURL); (@XQ]S}L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Tph^o^  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,b!D8{W"N  
String sProperty = "bytes="+nStartPos+"-"; V 9$T=[  
httpConnection.setRequestProperty("RANGE",sProperty); |;~=^a3?q  
Utility.log(sProperty); i8e*9;4@  
T{Xd>  
pZ|{p{_j  
InputStream input = httpConnection.getInputStream(); o{#aF=`{  
//logResponseHead(httpConnection); xtP:Q9!N  
zw15r" R  
) dk|S\  
byte[] b = new byte[1024]; 9!X3Cv|+L  
int nRead; uOzoE_i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B_ict)}ld  
{ !xck ~EAS  
nStartPos += fileAccessI.write(b,0,nRead); Z[*unIk  
//if(nThreadID == 1) p =nbsS~":  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f4P({V  
} ^zV_ vB)n  
C\5G43`  
QyVAs;  
Utility.log("Thread " + nThreadID + " is over!"); )S+fc=  
bDownOver = true; ]m1p<*0I$  
//nPos = fileAccessI.write (b,0,nRead); SgxrU&::  
} Fdhgm{Y2s  
catch(Exception e){e.printStackTrace ();} R`<2DC>h9  
} 7BU7sQjs  
} kVWcf-f  
E& 6I`8  
z7IJSj1gQI  
//打印回应的头信息 xD&n'M]  
public void logResponseHead(HttpURLConnection con) ;G8H' gM07  
{ kHhp;<  
for(int i=1;;i++) Ny7*MZ-  
{ T>% 5<P  
String header=con.getHeaderFieldKey(i); hJxL|5Uo  
if(header!=null) Mw RLv,&"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *h0D,O"0  
Utility.log(header+" : "+con.getHeaderField(header)); RN-gZ{AW  
else .8s-)I  
break; f#:3 TJV  
} %f&Y=  
} HBe*wkPd  
Sk+XBX(}  
axUj3J>  
public void splitterStop() 1-E6ACq  
{ r9{@e^Em  
bStop = true; 7OmT^jV2  
} I{dy,\p  
j3 6Y Iz$a  
Z}!'fX."  
} x@q.u3o9  
Z S=H1  
k)7i^ 1U  
/* 7oF3^K'S  
**FileAccess.java d*{Cv2A.  
*//文件访问(定位,写) <!RkkU& 6  
package NetFox; 7uc\AhOk6  
import java.io.*; ~wuCa!!A  
EQlb:;j  
N8Rq7i3F?a  
public class FileAccessI implements Serializable{ }p6]az3  
Lp:VU-S  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8WQ#)  
RandomAccessFile oSavedFile; #[9UCX^=  
long nPos; lfDd%.:q4S  
_1E c54D  
F_:zR,P%#  
public FileAccessI() throws IOException X,VI5$  
{ nm#23@uZ4K  
this("",0); WRu(F54Sk  
} `ZEFH7P  
M}[Q2v\  
8d5#vm  
public FileAccessI(String sName,long nPos) throws IOException ,e'm@d$Q*  
{ \0 h>!u  
oSavedFile = new RandomAccessFile(sName,"rw");  CA igV$  
this.nPos = nPos; 2o<*rH  
oSavedFile.seek(nPos); K_L7a>Fr  
} lfM vNv  
KDEyVYO:  
n~yHt/T  
public synchronized int write(byte[] b,int nStart,int nLen) cy,6^d  
{ n(Nu  
int n = -1; :1qLRr  
try{ sG#Os  
oSavedFile.write(b,nStart,nLen); ?1\I/ 'E9  
n = nLen; 3v_j*wy  
} / Q@4HV  
catch(IOException e) eG(YORkR  
{ /~'C!so[v  
e.printStackTrace (); r~T!$Tb  
} LAk .f  
"W6cQsi  
?9{^gW4|  
return n; el5Pe{j '  
} ^V;r  
cwvJH&%0  
5lHt~hB\  
} a({Rb?b  
wwdmz;0S  
P<R^eLZ<&  
/* DI8I'c-P  
**SiteInfoBean.java Wtu-g**KN  
*/ 9{fP.ifdv7  
package NetFox; Ao ?b1VYy/  
@ xo8"kl  
'L O3[G{  
public class SiteInfoBean { -S]ercar  
`?=3[  
A nl1+  
private String sSiteURL; //Site's URL ]*a(^*}A%  
private String sFilePath; //Saved File's Path 0O'M^[=d.8  
private String sFileName; //Saved File's Name #0r^<Yn  
private int nSplitter; //Count of Splited Downloading File {'zS8  
7#"NKxb  
:|5 m"X\  
public SiteInfoBean() cu}(\a  
{//nSplitter的缺省值为5 UUWRC1EtI  
//default value of nSplitter is 5 >b\|%=(x!*  
this("","","",5); I52nQCXi  
} 0);5cbV7i  
-<x%  
o0No"8DnjH  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l,Q`;v5|  
{ 31^/9lb  
sSiteURL= sURL; fIpS P@$<  
sFilePath = sPath; ~_;.ZZ-H]  
sFileName = sName; GtmoFSZ  
this.nSplitter = nSpiltter; `/m] K ~~  
]vcT2lr]  
/[Fk>Vhp  
} ^3sv2wh^|8  
?pJ2"/K   
Ma?uB8o+~  
public String getSSiteURL() $9\8?gS  
{ HHw&BNQG  
return sSiteURL; gLt6u|0q  
} hO> q|+mC  
~ a 2A"#f  
oNXYBeu+  
public void setSSiteURL(String value) Iw[zN[oz  
{ 9-j-nx @)  
sSiteURL = value; 0aR.ct%  
} .6[8$8c  
.sit5BX  
nl2Lqu1  
public String getSFilePath() +~F>:v?Rh  
{ #"A`:bjG  
return sFilePath; 5);"()g32  
} IW n G@!  
iDDq<a.A  
P2ySjgd  
public void setSFilePath(String value) vRaxB  
{ 4 w*m]D{  
sFilePath = value; }L Q%%  
} B_Gcz5  
fGj66rMGw  
Se[=$W  
public String getSFileName() [%LGiCU]  
{ `@\FpV[|P  
return sFileName; m-C#~Cp36  
} !4^Lv{1QZ  
Ye|gW=FUR  
0?FJ ~pu  
public void setSFileName(String value) G@D8 [  
{ 8}[<3K%*g  
sFileName = value; &VU^d3gv~  
} ok,O/|E}?  
}@$CS5w  
>nehyo:#  
public int getNSplitter() ]c_lNHssmq  
{ ~,F]~|U7l  
return nSplitter; #bGYHN  
} # r>)A  
2PPb  
C4X3;l Z%S  
public void setNSplitter(int nCount) +{6:]  
{  1l}Am>}  
nSplitter = nCount; VZamR}x  
} dXn$XGF%R  
} -k>k<bDAI  
r.LOj6c  
3:sc%IDP  
/* 1A;,"8kBd  
**Utility.java XH0Vs.w  
*/ c;29GHs2  
package NetFox; o|84yT!~  
A0.xPru1p  
7Fa<m]k  
public class Utility { GdScYAC   
_{LmJ?!  
7]5+%[Dg!  
public Utility() ~PpU'[  
{ !: vQg+S  
b+AxTe("  
4u2_xbT  
} #EKnjh=Uq  
e=jtF"&  
//线程睡眠 qoph#\  
public static void sleep(int nSecond) fk2Uxg=[  
{ C_[ d  
try{ ?<0'h{zNy  
Thread.sleep(nSecond); 3M^`6W[;  
} ze+S_{  
catch(Exception e) #\="^z6  
{ lzFg(Ds!f  
e.printStackTrace (); }]=A:*jD  
} [;toumv  
} (Ze\<Y#cv  
`"~X1;  
//日志 7|J&fc5BP  
public static void log(String sMsg) i7\>uni  
{ a(JtGjTf&  
System.err.println(sMsg); ~d3BVKP5  
} Z>NA 9:  
F')E)tV  
E}36  
public static void log(int sMsg) |~Awm"  
{ u91  
System.err.println(sMsg); Jx&+e,OST  
} x41t=E](  
} "1P2`Ep;  
_ -ec(w~/  
(d <pxx  
/* -%VFC^'5  
**TestMethod.java k]TJL9Q  
*/ tJGPkeA  
package NetFox; N7s9"i  
1mEW]z  
O1]XoUH<  
public class TestMethod { 9 771D  
aO<H!hK  
cwUor}<|  
public TestMethod() !VfVpi+-  
{ ///xx/weblogic60b2_win.exe )pey7-P7g5  
try{ `AdHyE  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2NL|_W/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;ov}%t>UD  
SiteFileFetch fileFetch = new SiteFileFetch(bean); pAEJ=Te  
fileFetch.start(); ~3Z(0 gujD  
} YWq{?'AaR  
catch(Exception e){e.printStackTrace ();} giN(wPgYP  
sg]g;U  
@[rlwwG,  
} [9p@uRE  
mL, {ZL ^  
l4^8$@;s  
public static void main(String[] args) ,6U=F#z  
{ hn/SS  
new TestMethod(); Qbj:^{`>(  
} zWdz9;=_  
} m]\d9%-AT&  
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