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http断点续传简单实现(java)

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/* NftR2  
**SiteFileFetch.java 0?''v>%  
*/ :cA8[!  
package NetFox; Hv*+HUc(:  
import java.io.*; _4LDzVjNRe  
import java.net.*; `^ )oVs  
v<ati c  
nFjaV`6`@  
public class SiteFileFetch extends Thread { 2UMX%+ "J  
>&JS-j Fg  
^V"08  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2E.D0E Cu  
long[] nStartPos; //开始位置 r@CbhD  
long[] nEndPos; //结束位置 qhmA)AWG>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #TIlM]5%  
long nFileLength; //文件长度 s,j=Kym%  
boolean bFirst = true; //是否第一次取文件 L-|u=c-6  
boolean bStop = false; //停止标志 E8.1jCL>{"  
File tmpFile; //文件下载的临时信息 o;v_vCLO  
DataOutputStream output; //输出到文件的输出流 _o-01gu.  
D.YT u$T  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -yMD9b  
public SiteFileFetch(SiteInfoBean bean) throws IOException ^ x_+ &  
{ lrmz'M'  
siteInfoBean = bean; W"g@*B'|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8Ib5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~V/?/J$  
if(tmpFile.exists ()) h@{CMe  
{ #VuiY  
bFirst = false; m,SWG[~  
read_nPos(); (wp?tMN5#  
} bKQ-PM&I/t  
else mW#p&{  
{ `<?((l%;R  
nStartPos = new long[bean.getNSplitter()]; FD.L{  
nEndPos = new long[bean.getNSplitter()]; Lmc"q FzK  
} lmx'w  
{WuUzq`  
u:>*~$f   
?ehUGvV2  
} (y?`|=G-xT  
y<)q;fI7  
)C>M74Bt  
public void run() b\+9#)Up@  
{ `3vt.b  
//获得文件长度 b@[\+P] "  
//分割文件 ?r R, h{~  
//实例FileSplitterFetch 9]|G-cyt  
//启动FileSplitterFetch线程 Tl*FK?)MC^  
//等待子线程返回 ;CA7\&L>  
try{ E>rWm_G  
if(bFirst) gX]'RBTb  
{ "0{t~?ol  
nFileLength = getFileSize(); T0BM:ofx  
if(nFileLength == -1) W4=<hB  
{ 7;NvR4P%  
System.err.println("File Length is not known!"); B3yp2tncj  
} +w+qTZyky  
else if(nFileLength == -2) xcN >L  
{ &uxwz@RC0  
System.err.println("File is not access!"); Mh5 =]O+  
} xJ)vfo  
else R1\$}ep^  
{ ET q~, g'  
for(int i=0;i<nStartPos.length;i++) -42jeJS  
{ ?N@p~ *x  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !Baq4V?KN  
} ysQ8==`38i  
for(int i=0;i<nEndPos.length-1;i++) x2z%J,z@4  
{ >=ng?  
nEndPos = nStartPos[i+1]; g/x\#W  
} G 4 C 7  
nEndPos[nEndPos.length-1] = nFileLength; i)+2? <]  
} +FYhDB~m  
} &;oWmmvz{  
[X=Ot#?u ~  
{1]Of'x'  
//启动子线程 ZTP&*+d  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8(0q,7)y  
for(int i=0;i<nStartPos.length;i++) G1:2MPH  
{ Qrt> vOUE7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wvNddu>@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ceGo:Aa<)  
nStartPos,nEndPos,i);  JS!  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LxxFosi8  
fileSplitterFetch.start(); Fd@:*ER  
} Ov9kD0S  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D[R<H((  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >-YWq  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,a?$F1Z-  
nEndPos = " + nFileLength); "e~"-B7(\Y  
// fileSplitterFetch[nPos.length-1].start(); oj~0zJI  
Y7 `i~K;  
9oJ=:E~CP  
//等待子线程结束 j%OnLTZ  
//int count = 0; "6 fTZ<  
//是否结束while循环 `)s>},8W!  
boolean breakWhile = false; 7= x]p  
z'ZGN{L  
qddP-uN  
while(!bStop) =o+))R4  
{ 6z80Y*|eJ  
write_nPos(); mu =H&JC  
Utility.sleep(500); fF} NPl  
breakWhile = true; aqAWaO  
8k`rj;  
ok7yFm1\  
for(int i=0;i<nStartPos.length;i++) @}@J$ g  
{ I!sB$=n  
if(!fileSplitterFetch.bDownOver) -g]g  
{ Um9]X@z  
breakWhile = false; O8% Y .SK  
break; b_T?jCyW  
} naoH685R4  
} Qs.g%  
if(breakWhile) -l` 1j6  
break; f*^)0Po  
, *A',  
*eo<5YUHt  
//count++; wIT}>8o  
//if(count>4) *PJg~F%  
// siteStop(); 79 ZBVe(}  
} -O-qEQd  
xl~%hwBd  
S<V__Sv  
System.err.println("文件下载结束!"); PME ?{%&  
} 0cm+:  
catch(Exception e){e.printStackTrace ();} \#; -C<[b  
} (S[" ak  
jTJ]: EN  
Z;#Ei.7p|  
//获得文件长度 .<C}/Cl  
public long getFileSize() :LwNOuavN  
{ h[0,/`qb{  
int nFileLength = -1; :5`BhFAd  
try{ ~rX2oLw{&  
URL url = new URL(siteInfoBean.getSSiteURL()); -Vi"hSsUP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @i[z4)"S  
httpConnection.setRequestProperty("User-Agent","NetFox");  `9  
&k+'TcWm  
6n.W5 1g(s  
int responseCode=httpConnection.getResponseCode(); $MEKt}S  
if(responseCode>=400) t3)nG8> )  
{ j&. MT@  
processErrorCode(responseCode); FaNH+LPe  
return -2; //-2 represent access is error )TBG-<wt  
} \e/'d~F  
9j[%Y?  
/v1Rn*VF!  
String sHeader; 6NV- &0 _  
9 1r"-%(r  
^p0BeSRiy;  
for(int i=1;;i++) FasA f( 3  
{ {yy ^DlHb  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bS+by'Ea1W  
//Utility.log(in.readLine()); Dm1;mRS+  
sHeader=httpConnection.getHeaderFieldKey(i); y+XB  
if(sHeader!=null) n(gw%w+\7  
{ 0vs9# <&V  
if(sHeader.equals("Content-Length")) q=5#t~?  
{ +FWkhmTv  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Gv!* Qk4  
break; ~$N%UQn?b#  
} ~5HI9A4^  
} 0.+"K}  
else uOqWMRsoi  
break; 1CiK&fQ'  
} *FkG32k  
} aD~3C/?aW  
catch(IOException e){e.printStackTrace ();} m>gok0{pm  
catch(Exception e){e.printStackTrace ();} c8sY#I  
:o}J u}t  
a(X?N.w  
Utility.log(nFileLength); p AzPi  
; 2vHdN  
`um#}ify#  
return nFileLength; LX e{  
} )jK"\'cK  
38dXfl  
fmvX;0O  
//保存下载信息(文件指针位置)  ? {Lp  
private void write_nPos() &Z_W*D  
{ V@Z8t8  
try{ +'H_sMmi{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); qJj;3{X2  
output.writeInt(nStartPos.length);  t]Xdzy  
for(int i=0;i<nStartPos.length;i++) wwS{V  
{ ;/W;M> ^  
// output.writeLong(nPos); (63_  
output.writeLong(fileSplitterFetch.nStartPos); FLO#!G  
output.writeLong(fileSplitterFetch.nEndPos); )k0P' zGb  
} *f:^6h  
output.close(); bmotR8d  
} M$z.S0"  
catch(IOException e){e.printStackTrace ();} &j,rq?eh$  
catch(Exception e){e.printStackTrace ();} F7`3,SzHp  
} #;Y JR9VN  
<JKRdIx&1  
LXaT_3 ;  
//读取保存的下载信息(文件指针位置) /a\6&Eb  
private void read_nPos() yAoJ?<4^W  
{ :luVsQ  
try{ 8 kw`=wSH>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [Z484dS`_  
int nCount = input.readInt(); kScq#<Y&  
nStartPos = new long[nCount]; =N`"%T@=  
nEndPos = new long[nCount]; ]&1Kz 2/  
for(int i=0;i<nStartPos.length;i++) 3~\mP\/4v  
{ \iAkF`OC  
nStartPos = input.readLong(); rLNo7i  
nEndPos = input.readLong(); @<e+E"6  
} ] 5lp.#EB  
input.close(); k+2~=#  
} mvI[=e*  
catch(IOException e){e.printStackTrace ();} w4 <FC$  
catch(Exception e){e.printStackTrace ();} oBr/CW  
} vBUx )l  
2/qP:3)  
"#2z 'J  
private void processErrorCode(int nErrorCode) S*6P=O*  
{ 1Tf"<D p  
System.err.println("Error Code : " + nErrorCode); o~,dkV  
} sB ]~=vUP  
kC"<4U  
<8p53*a  
//停止文件下载 zCT Wi  
public void siteStop() imAsE;:  
{ ]lzt "[  
bStop = true; [K;J#0V+&L  
for(int i=0;i<nStartPos.length;i++) !CROc}  
fileSplitterFetch.splitterStop(); 7=t4;8|j;  
aEVBU  
|jV>  
} M"2Tuwz  
} ~k?7XF I  
//负责部分文件的抓取 n'{cU(  
**FileSplitterFetch.java (Bd8@}\u_  
*/ NH$a:>  
package NetFox; SsfnBCVR  
(7q!Z!2  
_6&x$ *O  
import java.io.*; ozF>2`K }  
import java.net.*;  2&O!<C j  
&a%|L=FY  
xSZgQF~  
public class FileSplitterFetch extends Thread { ^ElUU?rX  
W F<`CQg[  
40N8?kQ}?  
String sURL; //File URL 5BCXI8Ox9x  
long nStartPos; //File Snippet Start Position hex:e2x  
long nEndPos; //File Snippet End Position W[[3'JTF  
int nThreadID; //Thread's ID D)XF@z;  
boolean bDownOver = false; //Downing is over o ^L 3Xiv  
boolean bStop = false; //Stop identical tgH@|Kg  
FileAccessI fileAccessI = null; //File Access interface y^tuybpZY<  
Qx|m{1~-  
O^48c$Apv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x):cirwkl  
{ ";yCo0*  
this.sURL = sURL; 7udMF3;>  
this.nStartPos = nStart; Vm6G5QwM  
this.nEndPos = nEnd; r7/y'Y]O  
nThreadID = id; @dQIl#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I.TdYSB  
} >4`("#  
XtVx H4q  
l=U@j T  
public void run() 1GKd*z  
{ [!p>Id  
while(nStartPos < nEndPos && !bStop) #N_C| v/  
{ cq+|fg~Yy  
a}ogNx  
&U ]L@ ]x  
try{ xtYX}u  
URL url = new URL(sURL); fEE[h uG  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DcA{E8Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); *,X;4?:,  
String sProperty = "bytes="+nStartPos+"-"; jIwz G+)$P  
httpConnection.setRequestProperty("RANGE",sProperty); 0P^RciC f  
Utility.log(sProperty); (:Rj:8{  
AJt *48H*G  
:@{(^}N8u  
InputStream input = httpConnection.getInputStream(); JsI` #  
//logResponseHead(httpConnection); m07= _4  
yKF"\^`@  
Yo3my>N&g  
byte[] b = new byte[1024]; Cqy84!Z<  
int nRead; ms8de>A|H  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C-lv=FJEk/  
{ ;75K:_  
nStartPos += fileAccessI.write(b,0,nRead); Y~#m-y  
//if(nThreadID == 1) 4Ei*\:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^WQ.' G5Q  
} #qY`xH'>  
^JZ]?iny  
@ofivCc<%  
Utility.log("Thread " + nThreadID + " is over!"); .6aC2A]es  
bDownOver = true; n@  lf+  
//nPos = fileAccessI.write (b,0,nRead); 3 ha^NjE  
} kx0(v1y3gT  
catch(Exception e){e.printStackTrace ();} S[(Tpk2_  
} Z8*E-y0  
} Aon 3G  
P*Va<'{:{  
Jt5\  
//打印回应的头信息 <VI.A" Qk~  
public void logResponseHead(HttpURLConnection con) p A7&  
{ UIgs/  
for(int i=1;;i++) "1|n]0BF  
{ 2\80S[f  
String header=con.getHeaderFieldKey(i); }A,9`  
if(header!=null) F \6-s`(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); chk1tFV  
Utility.log(header+" : "+con.getHeaderField(header)); _K["qm{X_  
else -J*BY2LU3f  
break; U Hh  
} (~ro_WC/I  
} ,Z*&QR  
*Z'*^Y1le  
4{4VC"fa  
public void splitterStop() .anXsjD%W  
{ DCr&%)Ll  
bStop = true; E{x<P0 ;  
} hB/4.K]8  
pFb }5Q  
__N< B5E  
} -P#PyZEH&I  
Ahl-EVIr<  
"IQ' (^-P  
/* >dO1)  
**FileAccess.java R5OP=Q8  
*//文件访问(定位,写) r Q)?Bhf  
package NetFox; ZLm?8g6-  
import java.io.*; nk=+6r6  
*UBukn  
,5}%_  
public class FileAccessI implements Serializable{ ZNWo:N8;  
&%eWCe+ +  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @GTkS!86  
RandomAccessFile oSavedFile; +I~`Ob  
long nPos; [ye!3h&]  
pY@$N&+W  
-u+@5K;^Y  
public FileAccessI() throws IOException 2tPW1"M.n  
{ N8*6sK.  
this("",0); J:W|2U="  
} v *'anw&Z  
aia`mO]  
HK}br!?  
public FileAccessI(String sName,long nPos) throws IOException 2S%[YR>>  
{ |q| ?y`X4/  
oSavedFile = new RandomAccessFile(sName,"rw"); h&5bMW  
this.nPos = nPos; Hwb+@'o  
oSavedFile.seek(nPos); 1M@OBfB8  
} VZveNz@]r  
zD}@QoB  
X=C*PWa7  
public synchronized int write(byte[] b,int nStart,int nLen) ?XCFR t,ol  
{ \e)>]C}h  
int n = -1; 9mA6nmp  
try{ HrOq>CSR  
oSavedFile.write(b,nStart,nLen); i28WgDG)5  
n = nLen; A]<+Aq@{  
} )ZZjuFQJ)  
catch(IOException e) R:N4_4& C~  
{ d `MTc  
e.printStackTrace (); J!{"^^*  
} GgT 5'e;N  
+lYo5\1=  
uX/K/4  
return n; JRgrg &#  
} I:|<};m m  
h@kq>no  
WZ@hP'Zc  
} I1f4u6\*X  
}xx"  
 ujin+;1  
/* gm^j8  B  
**SiteInfoBean.java 6DkFIkS  
*/ *sJT\J$D[  
package NetFox; gWk?g^KJL  
0Y>5&  
pseN!7+or  
public class SiteInfoBean { bm>N~DC  
{UeS_O>(  
lIhP\:;S&  
private String sSiteURL; //Site's URL g49G7sk  
private String sFilePath; //Saved File's Path I3I1<}>]Z  
private String sFileName; //Saved File's Name Yamu"#  
private int nSplitter; //Count of Splited Downloading File X&LaAqlSG  
k2 _i;v  
cePe0\\  
public SiteInfoBean() 6 4,('+  
{//nSplitter的缺省值为5 oMNt676  
//default value of nSplitter is 5 !k3 eUBF  
this("","","",5); cy-o@U"s8  
} UWXl c  
Ei HQ&u*  
#zf,%IYF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I%|,KWM  
{ nmo<t]  
sSiteURL= sURL; `{KdmWhW  
sFilePath = sPath; @> |3d  
sFileName = sName; n[K LY!  
this.nSplitter = nSpiltter; bmzY^ %a  
| V: 9 ][\  
:kMF.9U:  
} W(jOD,QMB  
}/bxe0px  
1a gNwFd~  
public String getSSiteURL() )5[OG7/g  
{ c 80Ffq  
return sSiteURL; gf ?_tB0C  
} ROhhd.  
F$sDmk#  
+^<s'  
public void setSSiteURL(String value) H:#sf][&,L  
{ !kxJ&VmeF  
sSiteURL = value; P @Jo[J<  
} %O|+` "  
0SV<Pl^  
eF"k"Ckt'  
public String getSFilePath() 3<x1s2U  
{ $2E&~W %  
return sFilePath; 41v#|%\w  
} 1j*E/L  
y3 "+4e  
a$=He   
public void setSFilePath(String value) ^qY?x7mx1  
{ eH_< <Xh!v  
sFilePath = value; XfQK kol  
} L`"j> ),  
gs"w 0[$  
I}sb0 Q&  
public String getSFileName() _. &N@k  
{ *Y':raP  
return sFileName; gF>t+"+ x  
} m9=93W?   
Pi hpo  
J#DN2y <  
public void setSFileName(String value) )Drif\FF)  
{ H?_wsh4J  
sFileName = value; #|"M  
} (zX75QSKV  
t-i\gq^  
gX|We}H  
public int getNSplitter() N mA6L+  
{ |{ @BH  
return nSplitter; z*)kK  
} N(l  
eakQZ-Q  
r3NdE~OAi  
public void setNSplitter(int nCount) "x0/i?pqa  
{ D0}r4eA  
nSplitter = nCount; /o^/ J~/3  
} _+9o'<#u(  
} >} E  
G3o`\4p  
}60/5HNr  
/* $jOp:R&I^3  
**Utility.java r+!29  
*/ O+?vQ$z  
package NetFox; Jr=XVQ(F  
!C@+CZXLx  
{G+iobQdd  
public class Utility { 9S|a!9J  
[]$L"?]0uk  
 u]OYu  
public Utility() +~V)&6Vn  
{ IuY4R0Go  
&^7(?C' u  
Qd/x{a8  
} 4" pU\g  
-%dBZW\u2  
//线程睡眠 !;UoZ~  
public static void sleep(int nSecond) w$Z%RF'p  
{ "QvTn=  
try{ N F,<^ u  
Thread.sleep(nSecond); CiV^bYi  
} ^ib =fLu  
catch(Exception e) mqtYny'  
{ &3OV|ly]  
e.printStackTrace (); dJe 3DW :  
} _SnD)k+TgJ  
} :=*V i`  
ZfXgVTJ`  
//日志 &x\cEI)!  
public static void log(String sMsg) 4t-l@zFWb  
{ #5=W[+4eN  
System.err.println(sMsg); CFUn1^?0  
} [1mEdtqf*  
V`8\)FFG  
c#f@v45  
public static void log(int sMsg) x!6<7s  
{ vY7 @1_"  
System.err.println(sMsg); X}wo$t  
} 4y.qtiIP>$  
} &smZ;yb|'h  
~e&O?X  
A&A{Thz  
/* ~9PZ/( '  
**TestMethod.java pekNBq Wm  
*/ ?AH B\S  
package NetFox; l.P;85/+  
IL1iTR H  
-Jf}3$Ra  
public class TestMethod { 1aZGt2;  
D"2bgw  
w"37sv  
public TestMethod() H>Ucmd;ay  
{ ///xx/weblogic60b2_win.exe dUUg}/  
try{ ' &3,qT  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ia (&$a8X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ROXa/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~uV(/?o%  
fileFetch.start(); 1IlOU|4  
} E3] 8(P%D-  
catch(Exception e){e.printStackTrace ();} :5F(,Z_  
l"7#(a  
U~d%5?q  
} >=:^N-a  
_Ie:!q  
sm;kg=  
public static void main(String[] args) H@u5&  
{ e,r7UtjoxR  
new TestMethod(); s7sTY   
} a`[9<AM1#  
} h?H|)a<^9  
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