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http断点续传简单实现(java)

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/* .s4hFB^n  
**SiteFileFetch.java }$K2h*  
*/ % -~W|Y  
package NetFox; +39Vxe:Oy  
import java.io.*; -Yaw>$nJ  
import java.net.*; x+V;UD=mH  
>U~B"'!xV  
_":yUa0D  
public class SiteFileFetch extends Thread { 'qTMY*  
)PC(1Zn  
u-W6 hZ$  
SiteInfoBean siteInfoBean = null; //文件信息Bean :Zy7h7P,lT  
long[] nStartPos; //开始位置 )"  H$1  
long[] nEndPos; //结束位置 ]Gw?DD|Gn  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 nZF(92v  
long nFileLength; //文件长度 b P>!&s_  
boolean bFirst = true; //是否第一次取文件 ILt95l  
boolean bStop = false; //停止标志  } z4=3 '  
File tmpFile; //文件下载的临时信息 UOn L^Z}  
DataOutputStream output; //输出到文件的输出流 !P7##ho0  
-.A8kJ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) c65_E<5Z  
public SiteFileFetch(SiteInfoBean bean) throws IOException S- Mh0o"  
{ xO2S|DH{  
siteInfoBean = bean; =e7,d$i  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ZeD""vJRY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )oOcV%  
if(tmpFile.exists ()) N0be=IO5#  
{ zcrLd={  
bFirst = false; -e=p*7']  
read_nPos(); LGN,8v<W(  
} /K mzi9j+  
else ETP}mo  
{ d*26;5~\  
nStartPos = new long[bean.getNSplitter()]; "7R"(.~>  
nEndPos = new long[bean.getNSplitter()]; 5YJn<XEc  
} @l9qH1  
0NLoqq  
_C9*M6IU  
KlgPDV9mg  
} e&dE>m  
QN[-XQ>Xt  
}?,Gn]]  
public void run() I At;?4  
{ Cc:4n1|]>  
//获得文件长度 fP`g#t)4Tu  
//分割文件 /^~3Ib8Fw+  
//实例FileSplitterFetch lAsDdxB`  
//启动FileSplitterFetch线程 rs01@  
//等待子线程返回 ,63hO.4M  
try{ q# W|*kL3  
if(bFirst) 7<Fp3N 3  
{ pv2_A   
nFileLength = getFileSize(); DXlP (={*  
if(nFileLength == -1) E3gR%t  
{ .O [RE_j  
System.err.println("File Length is not known!"); `BKo`@  
} G| pZ  
else if(nFileLength == -2) }$W4aG*[  
{ a^qLyF& F  
System.err.println("File is not access!"); \Q"o\:IoIT  
} [>"bL$tlo*  
else >;',U<Wd  
{ $AAv%v  
for(int i=0;i<nStartPos.length;i++) ?2VY ^7N[  
{ i^9PiP|U  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); O YGh!sW  
} (yFR;5Fo  
for(int i=0;i<nEndPos.length-1;i++) -k{n"9a9?  
{ aG7QLCL  
nEndPos = nStartPos[i+1]; u7>b}+ak&  
} D'aq^T'  
nEndPos[nEndPos.length-1] = nFileLength; ~LPxVYhK  
} ~ \tI9L?|A  
} -;_`>OU{  
6#XB'PR2p  
ODK$G [-  
//启动子线程 &?^S`V8R*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E 3b`GRay  
for(int i=0;i<nStartPos.length;i++) Y) Y`9u<?  
{ <@FOqi{o{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Vyv)#32o3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), orn9;|8q  
nStartPos,nEndPos,i); oxE'u<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;crQ7}k  
fileSplitterFetch.start(); $x5P5^Y  
} n(.y_NEgV!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2wE?O^J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]]{$X_0n  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D3V5GQ\=  
nEndPos = " + nFileLength); 0es[!  
// fileSplitterFetch[nPos.length-1].start(); X3#/|>  
FL!W oTB  
'3Yci(t+  
//等待子线程结束 I|lz;i}$  
//int count = 0; Z~{0XG\Y  
//是否结束while循环 2g1[ E_?  
boolean breakWhile = false; <A&mc,kj  
i"%X[(U7  
/_E8'qlx  
while(!bStop) LZm6\x  
{ @s J[<V  
write_nPos(); `e]L.P_e?  
Utility.sleep(500); v4!zB9d  
breakWhile = true;  t4pc2b  
_ngyai1  
D.o|pTZ  
for(int i=0;i<nStartPos.length;i++) }fnp}L  
{ trmCIk&Fkj  
if(!fileSplitterFetch.bDownOver)  lk{  
{ 2?ac\c6"  
breakWhile = false; ]Mi ~vG q  
break; ?P[uf  
} _f$8{&`k  
} `m?%{ \  
if(breakWhile) `;b@a<Wl  
break; {4Y@ DQ-  
p+U}oC  
Z8nj9X$   
//count++; k|Vq-w  
//if(count>4) Zh`lC1l'  
// siteStop(); / ]_T  
} 1"3|6&=  
^RytBwzKM  
. $uvQpyh  
System.err.println("文件下载结束!"); LziEF-_  
} Gwxx W   
catch(Exception e){e.printStackTrace ();} |cStN[97%  
} #}L75  
}\}pSqW  
`E>HpRcxD  
//获得文件长度 L<!}!v5ja  
public long getFileSize() ZB GLwe  
{ C J S  
int nFileLength = -1; _x 'R8/  
try{ pkpD1c^  
URL url = new URL(siteInfoBean.getSSiteURL()); <m9hM?^q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SV16]Vc  
httpConnection.setRequestProperty("User-Agent","NetFox"); j*>+^g\Q6  
Kdk0#+xtP  
:S}!i?n  
int responseCode=httpConnection.getResponseCode(); 0F-X.Dq  
if(responseCode>=400) RvKP&  
{ $A"kHS7T  
processErrorCode(responseCode); ?D-1xnxep  
return -2; //-2 represent access is error duB{ 1  
} !/+ZKx("9  
i`/_^Fndyu  
<uUQ-]QOIh  
String sHeader; l CHaRR7  
90> (`pI=  
3^ ~M7=k  
for(int i=1;;i++) By{zX,6'  
{ Vrn. #d  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qPZ'n=+  
//Utility.log(in.readLine()); W)3?T& `  
sHeader=httpConnection.getHeaderFieldKey(i); *LpEH,J  
if(sHeader!=null) 6s\niro2  
{ )orVI5ti  
if(sHeader.equals("Content-Length")) 3Yf&F([t  
{ ^%|,G:r  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M*FUtu  
break; P:h;"  
} 5ckL=q"+/  
} >c%OnA,3  
else W[BZ/   
break; 5vs~8|aRo  
} ~Q"3#4l  
} Bz<T{f  
catch(IOException e){e.printStackTrace ();} ^T@ (`H4@  
catch(Exception e){e.printStackTrace ();} bh|M]*Pq  
yQE|FbiA  
eznt "Rr2  
Utility.log(nFileLength); Hs/ aU_  
lo*OmAF  
AE`X4q  
return nFileLength; i2KN^"v?N  
} vdw5T&Q{{C  
I|69|^  
D/)wg$MI  
//保存下载信息(文件指针位置) x8k7y:  
private void write_nPos() 's>   
{ a5=8zO#%g  
try{ W_l/Jpv!W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); xY9 #ouF  
output.writeInt(nStartPos.length); Fb=(FQ2Y?  
for(int i=0;i<nStartPos.length;i++) 1BT]_ cP  
{ *I6z;.#  
// output.writeLong(nPos); n% zW6}  
output.writeLong(fileSplitterFetch.nStartPos); OE' ?3S  
output.writeLong(fileSplitterFetch.nEndPos); }U3+xl6g  
} rx2?y3pv  
output.close(); %@ UH,Ew  
} hw! l{yv  
catch(IOException e){e.printStackTrace ();} /ivcqVu]  
catch(Exception e){e.printStackTrace ();} _R&mN\ey5  
} yO*~)ALb+  
NRu _6~^^  
mM&Sq;JJ;  
//读取保存的下载信息(文件指针位置) {<&i4;  
private void read_nPos() @_s`@ ,=  
{ Ie{98  
try{ Z`x|\jI  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /j l{~R#1  
int nCount = input.readInt(); !>QS746S@  
nStartPos = new long[nCount]; fB^h2  
nEndPos = new long[nCount]; j6v|D>I  
for(int i=0;i<nStartPos.length;i++) -!MrG68  
{  [U9b_`  
nStartPos = input.readLong(); xi['knUi2-  
nEndPos = input.readLong(); VP0q?lh  
} MmiC%"7wt  
input.close(); wZ6D\I  
} rk$&sDc/3  
catch(IOException e){e.printStackTrace ();} o V"d%ks  
catch(Exception e){e.printStackTrace ();} xxjg)rVuy  
} e ewhT ^  
{gh41G;n  
AsFn%8_I  
private void processErrorCode(int nErrorCode) _CqVH5U?  
{ oSVo~F  
System.err.println("Error Code : " + nErrorCode); @>`+eg][?P  
} nOq?Q  
PL$*)#S"$  
8B#;ffkmN  
//停止文件下载 tLCu7%P>  
public void siteStop() u=_"* :}  
{ qLrvKoEX2  
bStop = true; 58xaVOhb  
for(int i=0;i<nStartPos.length;i++) Ku;|Dz/=o  
fileSplitterFetch.splitterStop(); HYVSi3[  
MKVz'-`u  
t Gt/=~n9  
} hojP3 [  
} ]xGo[:k|E  
//负责部分文件的抓取 $!Z><&^/  
**FileSplitterFetch.java *+(t2!yFmE  
*/ s18o,Zs'  
package NetFox; lGrp^  
;:<z hO  
|;xm-AM4r  
import java.io.*; )Z6bMAb0'N  
import java.net.*; ZEY="pf  
\8j5b+  
q5 eyle6  
public class FileSplitterFetch extends Thread { o95)-Wb  
i%BrnjX  
+c)"p4m  
String sURL; //File URL `=m[(CLb  
long nStartPos; //File Snippet Start Position x_za R}WI  
long nEndPos; //File Snippet End Position 6,C2PR_+  
int nThreadID; //Thread's ID ,RmXZnWY  
boolean bDownOver = false; //Downing is over Pdgn9  
boolean bStop = false; //Stop identical oCtg{*vp  
FileAccessI fileAccessI = null; //File Access interface $cl[Qcw  
;]*V6!6RR  
/V'^$enK!}  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U@t" o3E  
{ Xjb 4dip  
this.sURL = sURL; 8yW8F26  
this.nStartPos = nStart; -64@}Ts*?  
this.nEndPos = nEnd; /<[S> ;!kr  
nThreadID = id; &6]+a4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~K'e}<-G  
} feJzX*u  
9Z?P/ o  
7D'-^#S5  
public void run() /#mq*kNIM6  
{ mCM7FFl I  
while(nStartPos < nEndPos && !bStop) b1+6I_u.  
{ q/T(s  
` =ocr8c  
-NzO,?  
try{ Dl C\sm  
URL url = new URL(sURL); Zl,c+/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WP(+jL^-  
httpConnection.setRequestProperty("User-Agent","NetFox"); 'Cki"4%<  
String sProperty = "bytes="+nStartPos+"-"; 'u9,L FO  
httpConnection.setRequestProperty("RANGE",sProperty); $ ~>3bik@  
Utility.log(sProperty); a[e&O&Z  
hz:^3F`>/&  
$'Pn(eZHGv  
InputStream input = httpConnection.getInputStream(); q%H`/~AYM  
//logResponseHead(httpConnection); G.j  R  
S8=Am7D]1  
$ghAC  
byte[] b = new byte[1024]; m(2(Caz{  
int nRead; 6d4e~F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7JC^+ rk  
{ 48}L!m @  
nStartPos += fileAccessI.write(b,0,nRead); cb36~{  
//if(nThreadID == 1) ZD$W>'m{F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K &L9Ue  
} ! z!lQ~  
euxkw]`h6  
hbZ]DRg  
Utility.log("Thread " + nThreadID + " is over!"); Mn)>G36(  
bDownOver = true; Oup5LH!sW  
//nPos = fileAccessI.write (b,0,nRead); p#14  
} 8PN/*Sa  
catch(Exception e){e.printStackTrace ();} 0P MF)';R  
} "zN2+X"&  
} 1yFVF  
 L#  
yQP!Vt^  
//打印回应的头信息 aJ!(c}N~97  
public void logResponseHead(HttpURLConnection con) xXa* d  
{ S7|6dwQ&  
for(int i=1;;i++) xg:r5Z/|)  
{ 25bbuhss  
String header=con.getHeaderFieldKey(i); l7{]jKJue  
if(header!=null) f82$_1s^  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *HT )Au"5  
Utility.log(header+" : "+con.getHeaderField(header)); ?nVwT[  
else BIu%A]e"  
break; @ve4rc/LI  
} Ark+Df/  
} 1/ZvcdYB  
;Avz%2#c`  
YwbRzY-#F  
public void splitterStop() d]3c44kkK{  
{ j|6@>T1  
bStop = true; 6}V)\"u&   
} 4=; . <  
XwZ~pY ~  
WO}l&Q  
} {|R@\G.1(  
\>B$x@-wg  
t^8 ii  
/* Nu/D$m'PY  
**FileAccess.java o+NPe36  
*//文件访问(定位,写) 73n|G/9n[  
package NetFox; z XI [f  
import java.io.*; >"OwdAvX  
1q?b?.  
L9lNAiOH  
public class FileAccessI implements Serializable{ |*G$ilu  
dz3KBiq  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bCV3h3<  
RandomAccessFile oSavedFile; TT85G&#  
long nPos; Fi7G S;  
'zRi ;:UHA  
%i!=.7o.  
public FileAccessI() throws IOException .Lwp`{F/  
{ G,{=sFX  
this("",0); OpNTyKbaD  
} S":55YQev!  
#!A'6SgbkM  
qw#wZ'<n  
public FileAccessI(String sName,long nPos) throws IOException <yoCW?#  
{ sIVVF#0}]  
oSavedFile = new RandomAccessFile(sName,"rw"); Q140b;Z  
this.nPos = nPos; Sckt gp8  
oSavedFile.seek(nPos); DH@]d0N  
} O^Y}fo'  
=up!lg^M  
\d"uR@$3mG  
public synchronized int write(byte[] b,int nStart,int nLen) T[ ~8u9/  
{ A#b`{C~l  
int n = -1; *btLd7c%  
try{ QU#u5sX A  
oSavedFile.write(b,nStart,nLen); iY|zv|;]=  
n = nLen; {r.KY  
} BzVF!<!  
catch(IOException e) 4R c_C0O  
{ 3?}\Hw  
e.printStackTrace (); UQ7E7yY#  
} vb&1 S  
=XRTeIZ  
&Zzd6[G+  
return n; +vDEDOS1  
} +#B4Z'nT  
dy }O6  
QbN7sg~~  
} slQxz;t  
tny^sG/'  
 L+=pEk_  
/* \! *3bR  
**SiteInfoBean.java n?UFFi+a  
*/ u{asKUce\  
package NetFox; 6\+ ZTw  
jD<fu  
M1Frn n  
public class SiteInfoBean { %Voq"}}N  
Y=NXfTc  
;Dw6pmZ  
private String sSiteURL; //Site's URL \*wQ%_N5  
private String sFilePath; //Saved File's Path `<?{%ja  
private String sFileName; //Saved File's Name (TX\vI&  
private int nSplitter; //Count of Splited Downloading File u|.c?fW'3  
EgYM][:UU  
M0B6v} ^H  
public SiteInfoBean() LH:M`\(DL1  
{//nSplitter的缺省值为5 \68x]q[  
//default value of nSplitter is 5 Dc1tND$X3g  
this("","","",5); 2 cB){.E  
} <n+]\a97*  
x5X;^.1Fr  
>qqI6@h]c  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Juhi#&`T  
{ Mnv2tnU]  
sSiteURL= sURL; w!5@PJ)~U  
sFilePath = sPath; D*nNu]|j  
sFileName = sName; pv}k=wqJ1  
this.nSplitter = nSpiltter; t+H=%{z  
dj;Zzt3  
ZH1W#dt`[  
} 3iKy>  
\ZOH3`vq  
+,g"8&>  
public String getSSiteURL() ^xNs^wC.  
{ ,A{'lu  
return sSiteURL; :xBG~D  
} I,nW~;OV0  
?*nFz0cs^  
9B&fEmgEc?  
public void setSSiteURL(String value) W1$<,4j@M  
{ HCCEIgCT  
sSiteURL = value; + Cf  
} lMQ_S"  
[9lfR5=Xw[  
*l-f">?|  
public String getSFilePath() &A1~x!`  
{ >l>;"R9N  
return sFilePath; }|Ao@UvH  
} 4t]YHLBS  
<mk'n6B  
MS=zG53y  
public void setSFilePath(String value) MjNq8'$"  
{ d%EUr9~?  
sFilePath = value; (v@)nv]U  
} zK_+UT  
82>90e(CH]  
q!OB?03n  
public String getSFileName() 1Z$` }a  
{ K<g<xW*X  
return sFileName; Ofm?`SE*|  
} xh90qm  
>QcIrq%=  
Vzmw%f)_+  
public void setSFileName(String value) 7<Yf  
{ L3@upb  
sFileName = value; d41DcgG'j(  
} !Z}d^$  
CI}zu;4|  
4H]~]?F&  
public int getNSplitter() lG>,&(  
{ !#[=,'Y  
return nSplitter; `a+"[%  
} ;/79tlwq  
er%D`VHe  
)o;oOPT!  
public void setNSplitter(int nCount) `zw^ WbCO{  
{ Ocp`6Fj  
nSplitter = nCount; oZ!1^o3V  
} ElK7jWJ+  
} ~x #RIt  
YTk"'q-  
W[R^5{k`  
/* [d3i _^\  
**Utility.java nl\l7/}6  
*/ je[1>\3W  
package NetFox; e*Gt%'  
2K~<_.S  
]}za  
public class Utility { JK/VIu&!  
*%#Sa~iPo  
$-Yq?:  
public Utility() q-lejVS(g  
{ ?r}'0dW  
Ob~7r*q  
bZKlQ<sI  
} 6]D%|R,Q#}  
h@H8oZ[  
//线程睡眠 iu$:_W_  
public static void sleep(int nSecond) |ler\"Eu  
{ !Y95e'f.x  
try{ @L/p  
Thread.sleep(nSecond); e%wzcn  
} {pR4+g  
catch(Exception e) ~ 7^#.  
{ pFW^   
e.printStackTrace (); !!we4tWq  
} -H+<81"B#  
} dW4FMm>|  
tF&g3)D:NV  
//日志 %%c1@2G<  
public static void log(String sMsg) 0LW|5BVbIO  
{ }QzF.![~z  
System.err.println(sMsg); Q/2(qD; u  
} -KA Y  
"pa2,-&  
\}p!S$`  
public static void log(int sMsg) 1I#]OY#>  
{ 0g{`Qd  
System.err.println(sMsg); j YVR"D;  
} ;NJx9)7<  
} cmu|d  
p\).zuEf.  
m.g2>r`NU  
/* [(kC/W)!  
**TestMethod.java QrSF1y'd  
*/ , |lDR@  
package NetFox; L8WYxJ k  
S!@h\3d8{  
g7-*WN<  
public class TestMethod { W)z@>4`Bb  
">|G^ @|:A  
1. S?(1e"  
public TestMethod() E/:mO~1< c  
{ ///xx/weblogic60b2_win.exe M!D&a)\  
try{ AS-%I+ A  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xro%AM  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }1}L&M@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g-8D1.U  
fileFetch.start(); +!JTEKHKH  
} ~e;2gm  
catch(Exception e){e.printStackTrace ();} dZ6P)R  
6Qw5_V^0o  
Py^fWQ5I~%  
} +v{g'  
|J^}BXW'^)  
wOLA8UYW  
public static void main(String[] args) ^NB\[ &  
{ R[vA%G  
new TestMethod(); 0 YA  
} Po*G/RKu4W  
} ?? 2x*l1  
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