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http断点续传简单实现(java)

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/* ,deUsc  
**SiteFileFetch.java $o^e:Y , a  
*/ lEfBe)7+  
package NetFox; i=8UBryr'e  
import java.io.*; -3mgza  
import java.net.*; rR!U;  
@8"18HEp#  
a{`"68  
public class SiteFileFetch extends Thread { s#lto0b"8  
(^H5EeGV{  
m1e b8yX  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9bn2UiJ k  
long[] nStartPos; //开始位置 ;,0lUcV  
long[] nEndPos; //结束位置 {Bvm'lq`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9Q@*0-  
long nFileLength; //文件长度 S?,_<GD)w  
boolean bFirst = true; //是否第一次取文件 "2mFC!  
boolean bStop = false; //停止标志 feCqbWq:  
File tmpFile; //文件下载的临时信息 @\~tHJ?hQd  
DataOutputStream output; //输出到文件的输出流 + v[O  
?`A9(#ySM  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :^G%57NX  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,#aS/+;[)  
{ 6+ 8mV8{-8  
siteInfoBean = bean; \/,g VT  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 1D$::{h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); d_iY&-gq/  
if(tmpFile.exists ()) J v<$*TVS0  
{ Ofm5[q=  
bFirst = false; >h[(w  
read_nPos(); sA\L7`2H  
} gPUo25@pn*  
else Ea4 * o  
{ 6{7 3p@  
nStartPos = new long[bean.getNSplitter()]; ycjJbL(.  
nEndPos = new long[bean.getNSplitter()]; B+Q+0tw*i  
} XTj73 MWY  
!~d'{sy6  
+=, u jO:  
OMd# ^z  
} .b _?-Fv  
3G&0Ciet  
o PaZ  
public void run() wA r~<  
{ ! o^Ic`FhS  
//获得文件长度 0l1.O2 -  
//分割文件 u0 BMyH  
//实例FileSplitterFetch v?%3~XoH  
//启动FileSplitterFetch线程 .M+v?A d  
//等待子线程返回 &Y=.D:z<  
try{ 3`rIV*&_{  
if(bFirst) \c68n  
{ > i`8R  
nFileLength = getFileSize(); }3sN+4  
if(nFileLength == -1) gV.f*E1C  
{ qwP$~Bj  
System.err.println("File Length is not known!"); &>V/X{>$`K  
} 2C{/`N  
else if(nFileLength == -2) IM$0#2\  
{ j=Q$K #sBt  
System.err.println("File is not access!"); hpjUkGm5  
} b=_{/F*b?  
else :p&IX"Hh  
{ #|ddyCg2  
for(int i=0;i<nStartPos.length;i++) cdN/Qy  
{ !Y|8z\ Q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); fPrb%  
} Ivjw<XP6K  
for(int i=0;i<nEndPos.length-1;i++) H%cp^G  
{ yXXvs'$R \  
nEndPos = nStartPos[i+1]; 2R] XH 0   
} YnD#p[Wo^  
nEndPos[nEndPos.length-1] = nFileLength; *) } :l  
} bHJoEYY^  
} QnP{$rT  
I)rGOda{  
yP%o0n/"x  
//启动子线程 55,=[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4$F:NW,v:)  
for(int i=0;i<nStartPos.length;i++) shy  
{ ,wlbIl~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1w bTqc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ($:y\,5(9I  
nStartPos,nEndPos,i); 0IpST  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  Db,= 2e  
fileSplitterFetch.start(); Wk,6) jS=}  
} i[8NO$tN1)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b^%?S8]h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %awVVt{aG  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", []r T? -  
nEndPos = " + nFileLength); ?n&$m  
// fileSplitterFetch[nPos.length-1].start(); Liij{ahm  
1N>6rN  
'}T;b}&s  
//等待子线程结束 s{cKBau  
//int count = 0; ;*.(.  
//是否结束while循环 w'|&5cS  
boolean breakWhile = false; +!Q!m 3/I  
E;xMPK$  
l3BD <PB2S  
while(!bStop) 2DUr7r M  
{ [h^f%  
write_nPos(); C#ZhsWS!b  
Utility.sleep(500); 6{ C Fe|XN  
breakWhile = true; [pr 9 $Jr  
&7fY_~)B  
rQn{L{  
for(int i=0;i<nStartPos.length;i++) "NJ ,0A  
{ y%2%^wF  
if(!fileSplitterFetch.bDownOver) a6k(9ZF  
{ ^t`f1rGR  
breakWhile = false; )&XnM69~b  
break; j=FMYd8$y  
} Mq76]I%  
} \m%J`{Mt  
if(breakWhile) g%X&f_@  
break; ~c!Rx'  
G&.d)NfE  
jT{f<P0  
//count++; Lr wINVa  
//if(count>4) L>0!B8X2  
// siteStop(); kpl~/i`4  
} =?wMESU  
NoJUx['6  
I Jqv w  
System.err.println("文件下载结束!"); 6aRGG+H  
} P$6W`^D Z  
catch(Exception e){e.printStackTrace ();} ]c5DOv&  
} B'<!k7Ewy  
\y[Bu^tk  
~."!l'a  
//获得文件长度 lfXH7jL2~  
public long getFileSize() ]NbX`'  
{ ^=Q8]W_*  
int nFileLength = -1; r >E\Cco  
try{ hx*HY%\P  
URL url = new URL(siteInfoBean.getSSiteURL()); `i=JjgG@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^GE^Q\&D&  
httpConnection.setRequestProperty("User-Agent","NetFox"); =d}gv6v2S  
*Yj~]E0`1  
\5t`p67Ve_  
int responseCode=httpConnection.getResponseCode(); ESn6D@"  
if(responseCode>=400) D&4u63^  
{ D~5yj&&T;  
processErrorCode(responseCode); s Ke,  
return -2; //-2 represent access is error ? 7/W>  
} 3fm;r5  
x(rd$oZO  
aB=vu=hF  
String sHeader; iJ,M-GHK  
YR?3 61FK  
<9ePi9D(  
for(int i=1;;i++) h U 9\y  
{ N 9c8c  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q^*G`&w,  
//Utility.log(in.readLine()); *^X#Eb  
sHeader=httpConnection.getHeaderFieldKey(i); d&NCFx  
if(sHeader!=null) P4hZB_.=  
{ fL(':W&n-  
if(sHeader.equals("Content-Length")) Tld1P69(  
{ P{"  WlJ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0[V&8\S~'T  
break; &7$,<9.  
} D/gd  
} g&{gD^9)4  
else )?F $-~7  
break; NQDLI 1o  
} kX@ bv"i  
} K~`n}_:  
catch(IOException e){e.printStackTrace ();} UedvA9$&;  
catch(Exception e){e.printStackTrace ();} /!^L69um  
o9_(DJ<{  
4kWg>F3  
Utility.log(nFileLength); ]|Ow_z8 O  
BO?mQu~  
- P\S>G.  
return nFileLength;  KYnW7|*  
} Sg/:n,68  
!S~,> ,yd  
=$^Wkau  
//保存下载信息(文件指针位置) _7rqXkp%  
private void write_nPos() ;[;)P tFz\  
{ J ZVr&KZN  
try{ C$$"{FfgU"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fn1 ?Qp|  
output.writeInt(nStartPos.length); .tZjdNE(h  
for(int i=0;i<nStartPos.length;i++) cYZwWMzp  
{ wrz+2EP`  
// output.writeLong(nPos); !T<z'zZU  
output.writeLong(fileSplitterFetch.nStartPos); ` (7N^@  
output.writeLong(fileSplitterFetch.nEndPos); "}S9`-Wd|  
} [54@irH  
output.close(); IW5*9)N?  
} [>b  '}4  
catch(IOException e){e.printStackTrace ();} 2q`)GCES~  
catch(Exception e){e.printStackTrace ();} +CsI,Uf4*  
} >v^2^$^u  
c+@d'yR  
o,*folL  
//读取保存的下载信息(文件指针位置) 4y|xUO:  
private void read_nPos() 4(` 2#  
{ 9X 5*{f Y  
try{ a/`c ef  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j~+[uzW98  
int nCount = input.readInt(); iifc;62  
nStartPos = new long[nCount]; a"`g"ZRx  
nEndPos = new long[nCount]; ) 1lJ<g#  
for(int i=0;i<nStartPos.length;i++) Iq4Kgc  
{ 4 ?9soc  
nStartPos = input.readLong(); (Wm/$P;  
nEndPos = input.readLong(); &,W_#l{  
} D}zOuB,S  
input.close(); gGtep*k  
} SRA|7g}7W  
catch(IOException e){e.printStackTrace ();} 1Pud,!\%q  
catch(Exception e){e.printStackTrace ();} qWRNHUd  
} %00k1 *$  
Jo6~r-  
Ybs=W< -  
private void processErrorCode(int nErrorCode) 844tXMtPB\  
{ cJU!zG  
System.err.println("Error Code : " + nErrorCode); p{A}p9sjx  
} }4bB7,j  
v\vE^|-\/  
qT4I Y$h  
//停止文件下载 zznPD%#Sc  
public void siteStop() K$MJ#Zx^  
{ Bxn 8><  
bStop = true; pr0@sri@  
for(int i=0;i<nStartPos.length;i++) c[wQJc  
fileSplitterFetch.splitterStop(); OoAr%  
AIvL#12  
F<PWBs%  
} naec"Kut  
} <.PPs:{8#  
//负责部分文件的抓取 >>oASo  
**FileSplitterFetch.java <Dt /Rad  
*/ 1R5\GKF6o  
package NetFox; R$!;J?SS  
HI"!n$p  
2x<Qt2"  
import java.io.*; ,Az`6PW  
import java.net.*; Rxvd+8FF  
Ft%TnEp  
$I}Hk^X  
public class FileSplitterFetch extends Thread { xJ[k#?T'  
88tFB  
()@.;R.Z  
String sURL; //File URL 0[Xt,~  
long nStartPos; //File Snippet Start Position CX&yjT6`  
long nEndPos; //File Snippet End Position eZN3H"H  
int nThreadID; //Thread's ID < "L){$  
boolean bDownOver = false; //Downing is over ?)Czl4J  
boolean bStop = false; //Stop identical &xGfkCP.]  
FileAccessI fileAccessI = null; //File Access interface L}e"nzTE6I  
<B ]i80.  
877EKvsiC  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q G :jnl  
{ j=xtnIq  
this.sURL = sURL; \U)2 Tg  
this.nStartPos = nStart; @yU!sE:  
this.nEndPos = nEnd; Se^/VVm  
nThreadID = id; GvZac  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RvyBg:Aj5  
} y~]I Vl"  
C>w9 {h  
#.\,y>`  
public void run() [p( #WM:  
{ c-s`>m  
while(nStartPos < nEndPos && !bStop) 4! Oa4  
{  `5k6s,  
o@<6TlZM  
|"Xi%CQ2  
try{ w+).pcG( *  
URL url = new URL(sURL); dbMu6Bm\G  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BDRYip[Sa  
httpConnection.setRequestProperty("User-Agent","NetFox"); lJ2|jFY9  
String sProperty = "bytes="+nStartPos+"-"; #FQm/Q<0  
httpConnection.setRequestProperty("RANGE",sProperty); Kh:#S|   
Utility.log(sProperty); hSx+ {4PZ  
$+lz<~R  
6yu*a_  
InputStream input = httpConnection.getInputStream(); lry& )G=5  
//logResponseHead(httpConnection); }l]3m=)  
pU:C =hq4  
x;ICV%g/  
byte[] b = new byte[1024]; :{wsd$Qlj  
int nRead; 0XQ".:+h  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I9*BENkR  
{ zgq_0w~X  
nStartPos += fileAccessI.write(b,0,nRead); MUCJ/GF*  
//if(nThreadID == 1) v' 9(et  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c5=v`hv  
} !ulLGmUn  
5|6z1{g8  
Zeme`/aBb  
Utility.log("Thread " + nThreadID + " is over!"); PBAz` y2  
bDownOver = true; YL9t3 ]  
//nPos = fileAccessI.write (b,0,nRead); k[r./xEv+t  
} !dbA (  
catch(Exception e){e.printStackTrace ();} +/@ZnE9s  
} RK~FT/  
} shDt&_n  
R@7GCj  
JR a*;_  
//打印回应的头信息 (}~eD  
public void logResponseHead(HttpURLConnection con) wCq)w=,  
{ w371.84  
for(int i=1;;i++) *xv/b=  
{ 4ye`;hXy  
String header=con.getHeaderFieldKey(i); ?(,5eg  
if(header!=null) e&H<lT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (1elF)  
Utility.log(header+" : "+con.getHeaderField(header)); XftJ=  *  
else i"sYf9,  
break; N}l]Ilm$34  
} 3Q*RR"3  
} uZ0 $s$  
S\v&{  
St3(1mApl  
public void splitterStop() W kDn  
{ j6R{  
bStop = true; 6t7;}t]t  
} >+; b>  
4M0v1`k  
ZB^4(F')H  
} :E >n)_^  
>Rki[SNb-b  
,$6MM6W;-F  
/* JIY ^N9_  
**FileAccess.java hyvV%z Z  
*//文件访问(定位,写) ,I2re G  
package NetFox; jC/JiI  
import java.io.*; (;2J(GZ:$U  
{ck  
UB&S 2g  
public class FileAccessI implements Serializable{ rt@-Pw!B  
-4^@)~Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WW\)B-}T  
RandomAccessFile oSavedFile; dnX`F5zd  
long nPos; e}Af"LI  
vZ nO  
H8t{ >C)]  
public FileAccessI() throws IOException <E}]t,'3  
{ '9p5UC  
this("",0); mk`cyN>m  
} 9Pob|UA  
!iitx U  
bF Y)o Z  
public FileAccessI(String sName,long nPos) throws IOException kkE)zF   
{ $NGtxZp  
oSavedFile = new RandomAccessFile(sName,"rw"); bhm~Ii  
this.nPos = nPos; $jeDVH  
oSavedFile.seek(nPos); (fGJP*YO  
} SVs~,  
xwH|ryfs,Z  
6dS1\Y  
public synchronized int write(byte[] b,int nStart,int nLen) #`#aSqGmc  
{ dW^_tzfF7  
int n = -1; oIL+@}u7  
try{ E=1/  
oSavedFile.write(b,nStart,nLen); l#vw L15  
n = nLen; Q RmQ>  
} dT@SO  
catch(IOException e) SE}RP3dF!  
{ sO4}kxZ  
e.printStackTrace (); ! ?U^+)^$  
} |b'<XQ&l5  
k89gJ5B$  
(+Kof  
return n; '3_B1iAv  
} NK#"qK""k  
%]sEt{  
]BQWA  
} hPXVPLm7I  
a9EI7pnq  
*~<]|H5~  
/* E5[]eg~w%{  
**SiteInfoBean.java E=_B@VJknW  
*/ wyzBkRg.  
package NetFox; iJKm27 ">  
io?{ew  
s8_NN  
public class SiteInfoBean { gl7vM  
\,bFm,kC?  
Y %D*O  
private String sSiteURL; //Site's URL WWs[]zr  
private String sFilePath; //Saved File's Path g@6X|W5,J  
private String sFileName; //Saved File's Name wR<QeH'V  
private int nSplitter; //Count of Splited Downloading File :-W CW);N  
Jgv>$u  
`~+a=Q  
public SiteInfoBean() O7'^*"S  
{//nSplitter的缺省值为5 BM$tywC  
//default value of nSplitter is 5 , a_{ Y+  
this("","","",5); H.mQbD`X  
} xE-`Bb  
6k=Wt7C  
;Y XrG  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {6y.%ysU  
{ Q.E^9giC  
sSiteURL= sURL; p$o&dQ=n[  
sFilePath = sPath; [qD<U%Hi  
sFileName = sName; "T1#*"{j  
this.nSplitter = nSpiltter; H- qP>:  
pB7Z;&9  
8YLZ)k'  
} t5v)6|  
rKs WS~U  
?Nze P?g  
public String getSSiteURL() .L{+O6*c  
{ nIKT w  
return sSiteURL; dVtLYx  
} qjEWk."  
`::'UfHc  
d!z).G  
public void setSSiteURL(String value) H6\ x.J^,  
{ ihY^~  
sSiteURL = value; {*Wwu f.  
} )I-?zyL  
oS|~\,p"  
}~~^ZtJ\  
public String getSFilePath() )7%]<2V%  
{ u{nWjqrM*5  
return sFilePath; n6UU6t{  
} uZ?CVluP  
j72] _G  
+P)[|y +e  
public void setSFilePath(String value) !#gE'(J;c  
{ -%gd')@SfD  
sFilePath = value; nC{rs+P  
} /z?7ic0  
M"l rwun^  
oUKbzr/C  
public String getSFileName() 'CAukk|  
{ i|{nj\6w^  
return sFileName; 0uJzff!|  
} DCzPm/#b  
lJY=*KB(6  
<RVtLTd/  
public void setSFileName(String value) {1U*: @j  
{ *k]S{]Y  
sFileName = value; a`X&;jH0ef  
} =X5&au o  
&vvx"  
H^1 a3L]  
public int getNSplitter() f4y;K>u7p  
{ ygY+2  
return nSplitter; Qbpl$L  
} YYr&r.6  
E0A|+P '?  
SFgIY]  
public void setNSplitter(int nCount) bYB}A :  
{ (U(x[Df)  
nSplitter = nCount; r<"/P`r  
} ~teW1lMu(  
} EA E\Xv  
v]SE?xF{U  
6$<o^Ha*R  
/* ,fJ(.KI0  
**Utility.java WB [G!'  
*/ YaT+BRh?  
package NetFox; 'wnY>hN  
mKn357:  
F1*rUsRKN  
public class Utility { #TwE??ms  
]3u'Qv}o  
,(W98}nB  
public Utility() z\d2T%^:g(  
{ UKQ&TV}0  
2.2a2.I1  
3C[4!>|  
}  n(xlad  
:bDn.`KG#  
//线程睡眠 {^MAdC_  
public static void sleep(int nSecond) i*w-Q=  
{ 5T3>fw2G  
try{ t% B!\]  
Thread.sleep(nSecond); RAQ;O  
} Vzm+Ew _  
catch(Exception e) h`rjDd  
{ W&f Py%g  
e.printStackTrace (); |5B9tjJ"  
} at]Q4  
} H[k3)r2  
na:^7:I  
//日志 gH)B` @  
public static void log(String sMsg) $uB(@Ft.  
{  CyDf[C)=  
System.err.println(sMsg); 7[0k5-  
} [E1|jcmQ  
o"M^ sKz47  
U (7P X`1  
public static void log(int sMsg) 2Lgvy/uN  
{ n<&R"89  
System.err.println(sMsg); &+^ Y>Ke  
} <qY>d,+E'  
} ^uEl QI  
lG#&1  
lA 0_I"b2Y  
/* L([>yQZ  
**TestMethod.java gt(nZ  
*/ A8(PI)Ic.  
package NetFox; qk1D#1vl  
6mpUk.M"  
# h|< >  
public class TestMethod { \9zC?Cw  
yP]W\W'  
R3`W#`  
public TestMethod() {;M/J  
{ ///xx/weblogic60b2_win.exe iPpJ`i#@+  
try{ _cN)q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (kOv  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yS3s5C{C  
SiteFileFetch fileFetch = new SiteFileFetch(bean); v 8a  
fileFetch.start(); eW,Pn'  
} M= _CqK*  
catch(Exception e){e.printStackTrace ();} IOqyqt'  
XPTB,1g+f  
Dy@NgHe  
} =JH,RQ *  
wGX"R5  
}"H900WE|  
public static void main(String[] args) )pa|uH +N  
{ 1*b%C"C  
new TestMethod(); gRI|rDC)B  
} nDw9  
} VSFl9/5?  
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