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http断点续传简单实现(java)

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/* *%G$[=  
**SiteFileFetch.java Oz\mIVC#  
*/ `EV" /&`  
package NetFox; a@|/D\C  
import java.io.*; 9Tgl/}q)  
import java.net.*; /5:f[-\s  
]L'FYOfrpx  
U({20  
public class SiteFileFetch extends Thread { H-?wEMi)*u  
4H7 3a5f  
9;Z2.P"w  
SiteInfoBean siteInfoBean = null; //文件信息Bean dXkgWLI~  
long[] nStartPos; //开始位置 "4VC:"$f  
long[] nEndPos; //结束位置 'bH',X8gF  
FileSplitterFetch[] fileSplitterFetch; //子线程对象  0p8Z l  
long nFileLength; //文件长度 x=+R0ny  
boolean bFirst = true; //是否第一次取文件 a,o>E4#c  
boolean bStop = false; //停止标志 _xg4;W6M=  
File tmpFile; //文件下载的临时信息 }pE8G#O&  
DataOutputStream output; //输出到文件的输出流 @S/PB[%S  
q|E0Y   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  R^%uEP  
public SiteFileFetch(SiteInfoBean bean) throws IOException CaX0Jlk*  
{  u/ Os  
siteInfoBean = bean; ~c e?xr|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); '%W'HqVcG1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); U6hT*126  
if(tmpFile.exists ()) 4Xna}7  
{ <OKzb3e  
bFirst = false; x+kP,v  
read_nPos(); pNOVyyo>BW  
} 2<d l23  
else kI|Vv90l  
{ KY)r kfo B  
nStartPos = new long[bean.getNSplitter()]; "3!!G=s P  
nEndPos = new long[bean.getNSplitter()]; T5mdC  
} .YvE  
-qki^!Y?  
|E\0Rv{H3  
}3tbqFiH  
} CgLS2  
N=qe*Rlf  
vYh_<Rp5  
public void run() NF& ++Vr6  
{ 5zebH  
//获得文件长度 %5X}4k!p  
//分割文件 !i0jk,[B=  
//实例FileSplitterFetch /Q7cQ2[EU  
//启动FileSplitterFetch线程 ZE#f{qF(  
//等待子线程返回 j@1rVOmK  
try{ E,Q>jH  
if(bFirst) #!Iez vWf  
{ _Qy3A T~  
nFileLength = getFileSize(); )ca^%(25!z  
if(nFileLength == -1) +/A`\9QT  
{ tK<GU.+  
System.err.println("File Length is not known!"); < bHu9D  
} UWdPB2x[  
else if(nFileLength == -2) @PXb^x#k  
{ B]PTe~n^  
System.err.println("File is not access!"); H'Mc]zw_,  
} zj!&12w%3  
else #A8d@]Ps  
{ Cdjh/+!f  
for(int i=0;i<nStartPos.length;i++) 5xZ*U  
{ u$%>/cv  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,`7;S,f  
} cD-.thHO  
for(int i=0;i<nEndPos.length-1;i++) 8^fkY'x  
{ 9N9dQ}[:g  
nEndPos = nStartPos[i+1]; {VC4rA  
} &9CKI/K:  
nEndPos[nEndPos.length-1] = nFileLength; F+;{s(wx  
} By=/DVm)=  
} qyP|`Pm4  
zy(i]6  
2 }QD>  
//启动子线程 0y$aGAUm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sPCp20x:y8  
for(int i=0;i<nStartPos.length;i++) >uN`q1?l'  
{  \Vis  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &"dT/5}6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KKm0@Y   
nStartPos,nEndPos,i); CroI,=a&,  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gf]biE"k  
fileSplitterFetch.start(); ^(ks^<}  
} VjU;[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =RR225  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )!1; =   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J@ x%TA  
nEndPos = " + nFileLength); _C9*M6IU  
// fileSplitterFetch[nPos.length-1].start(); 3F,$} r#  
e&dE>m  
{mPalo A  
//等待子线程结束 }?,Gn]]  
//int count = 0; I At;?4  
//是否结束while循环 Cc:4n1|]>  
boolean breakWhile = false; q #f U*  
/^~3Ib8Fw+  
lAsDdxB`  
while(!bStop) +w Oa  
{ ,63hO.4M  
write_nPos(); t&UPU&tY  
Utility.sleep(500); 7<Fp3N 3  
breakWhile = true; pv2_A   
DXlP (={*  
E3gR%t  
for(int i=0;i<nStartPos.length;i++) gWp\?La  
{ +zxj-di M  
if(!fileSplitterFetch.bDownOver) q!#e2Dx  
{ 2 Mc/ah  
breakWhile = false; Sf>R7.lpP  
break; ?PNG@OK  
} !Gu,X'#Ab  
} u49zc9  
if(breakWhile) tE0DST/  
break; &x{CC@g/  
nu,#y"WQ  
qO=_i d  
//count++; #5GIO  
//if(count>4) (: IUg   
// siteStop(); ]%IcUd}  
} :ho)3kB  
UhCE.# U  
eR r.j  
System.err.println("文件下载结束!"); jR@j+p^e  
} X>mY`$!/  
catch(Exception e){e.printStackTrace ();} R}F0_.  
} !RLg[_'  
hkw;W[ZWa  
G l+[ |?N  
//获得文件长度 .$+]N[-=  
public long getFileSize() ZCi~4&Z#  
{ I]P'wav~O  
int nFileLength = -1; E6n3[Z  
try{ u-Pa:wm0-  
URL url = new URL(siteInfoBean.getSSiteURL()); o.t$hv|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |pJ)w  
httpConnection.setRequestProperty("User-Agent","NetFox"); qG7^XO Ws-  
.lfKS!m2  
ud K)F$7  
int responseCode=httpConnection.getResponseCode(); IM&2SSmYNH  
if(responseCode>=400) 3vPb}  
{ $:"r$7  
processErrorCode(responseCode); v_f8zk  
return -2; //-2 represent access is error gB@Xi*  
} 2"lDKjj  
FjIS:9^)t5  
<=8REA?  
String sHeader; 6k;__@B,  
*vFVXJo  
FblwQ-D  
for(int i=1;;i++) /_E8'qlx  
{ LZm6\x  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @s J[<V  
//Utility.log(in.readLine()); Pw/Z;N;:V  
sHeader=httpConnection.getHeaderFieldKey(i); UKp- *YukT  
if(sHeader!=null) Y - 6 ?x  
{ {J q[N}  
if(sHeader.equals("Content-Length")) !b0'd'xe  
{ 7''l\3mIn  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kH1hsDe|&y  
break; 3o%,8l,  
} YQOdwc LG  
} %3scz)4$  
else R0y={\*B5k  
break; 2b xkZS]  
} 'EJ8)2  
} O[f*!  
catch(IOException e){e.printStackTrace ();} Ed,`1+  
catch(Exception e){e.printStackTrace ();} f7 V36Q8  
ZzLmsTtzIu  
uZ( I|N$  
Utility.log(nFileLength); L+Yn}"gIs  
R*IO%9O  
Qj~m;F!  
return nFileLength; mdvooJ  
} 8RWfv}:X  
Gwxx W   
')t :!#  
//保存下载信息(文件指针位置) #}L75  
private void write_nPos() 6 ]W!>jDc  
{ |n=m{JX\m  
try{ ![3#([>4>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); :#58m0YLA:  
output.writeInt(nStartPos.length); V{;!vt~  
for(int i=0;i<nStartPos.length;i++) \y^Od7F  
{ F+Rtoq|  
// output.writeLong(nPos); I&]d6,  
output.writeLong(fileSplitterFetch.nStartPos); HXhz|s0  
output.writeLong(fileSplitterFetch.nEndPos); QlJ cj+_h  
} h`dtcJ0  
output.close(); {8UYu2t  
} *"` dO9Yf_  
catch(IOException e){e.printStackTrace ();} qLBXyQ;U  
catch(Exception e){e.printStackTrace ();} Y~Y-L<`I  
} #pP4\n-~hU  
F<q'ivj:w  
m\`dLrPX4j  
//读取保存的下载信息(文件指针位置) Twyx(~'&R  
private void read_nPos() R/r)l<X@  
{ p C l[DE  
try{ k@U8K(:x  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /e :V44  
int nCount = input.readInt(); >f#P(  
nStartPos = new long[nCount]; D].!u{##  
nEndPos = new long[nCount]; T:q_1W?h]  
for(int i=0;i<nStartPos.length;i++) YO7Y1(`  
{ Wr Ht  
nStartPos = input.readLong(); BDSZ'  
nEndPos = input.readLong(); }# 'wy  
} Kk1591'  
input.close(); /^^t>L  
} XL@i/5C[  
catch(IOException e){e.printStackTrace ();} Aifc0P-H  
catch(Exception e){e.printStackTrace ();} \Km!#:  
} e5KsKzu a  
3ny>5A!;2  
}S51yDVG_  
private void processErrorCode(int nErrorCode) ]|62l+  
{ bVmHUcR0  
System.err.println("Error Code : " + nErrorCode); [G2@[Ct Y1  
} S[,!  
z(2pl}  
OJiW@Z_\  
//停止文件下载 RY'f%c  
public void siteStop() _@9[c9bO  
{ A^:[+PJHN  
bStop = true; E^w2IIw  
for(int i=0;i<nStartPos.length;i++) F8M&.TE_3  
fileSplitterFetch.splitterStop(); y\K r@;q0w  
CsHHJgx  
r_nB-\  
} OV3l)73?t  
} v+uq  
//负责部分文件的抓取 i^Vb42%y  
**FileSplitterFetch.java M#X8Rs1`  
*/ "s!!\/^9C  
package NetFox; 52?zBl`|  
twElLOE  
-V0_%Smc  
import java.io.*; HA&7 ybl  
import java.net.*; Jb~$Vrdy  
Z- |.j^n  
0JzH dz  
public class FileSplitterFetch extends Thread { Oxs O  
.[&0FHnJ5  
!z">aIj\6  
String sURL; //File URL G2 A#&86J{  
long nStartPos; //File Snippet Start Position _DsA<SJ]  
long nEndPos; //File Snippet End Position YoyJnl.?u  
int nThreadID; //Thread's ID m;-FP 2~  
boolean bDownOver = false; //Downing is over h}-}!v  
boolean bStop = false; //Stop identical `G*7y7  
FileAccessI fileAccessI = null; //File Access interface zQ3m@x  
+GCN63 nX  
;6S,|rC ]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XN9s!5A<L)  
{ Y~\71QE>  
this.sURL = sURL; su;u_rc,  
this.nStartPos = nStart; R<. <wQ4I  
this.nEndPos = nEnd; 2%|  
nThreadID = id; Aq' yr,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zh`!x{Z?^  
}  8:=&=9%  
6. N?=R  
"fK`F/  
public void run() YXCltM E  
{ np2oXg%  
while(nStartPos < nEndPos && !bStop) e R Y2.!  
{ aT}Mn(F*?  
^X-3YhJ4U  
,/0Q($oz  
try{ rR`'l=,t  
URL url = new URL(sURL); \kSoDY`l&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GL;@heP  
httpConnection.setRequestProperty("User-Agent","NetFox"); y/=:F=H@w  
String sProperty = "bytes="+nStartPos+"-"; :})(@.H  
httpConnection.setRequestProperty("RANGE",sProperty); Z] ?Tx2|7  
Utility.log(sProperty); N(i%Oxp1  
q#LB 2M  
>[t0a"  
InputStream input = httpConnection.getInputStream(); ZK:dhwer  
//logResponseHead(httpConnection); W0e+yIaR  
g4b-~1[S  
?LJ$:u  
byte[] b = new byte[1024]; y cYT1Sg 8  
int nRead; 2iOn\ ^]x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1ocd$)B|}  
{ VB>KT(n-b  
nStartPos += fileAccessI.write(b,0,nRead); Q{%2Npvq  
//if(nThreadID == 1) dRw O t  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @z $,KUH  
} ( w4w  
y8} fj=  
7$3R}=Z`\q  
Utility.log("Thread " + nThreadID + " is over!"); S1jI8 #z}_  
bDownOver = true; =5:L#` .  
//nPos = fileAccessI.write (b,0,nRead); z4t.- 9(C  
} $t*>A+J  
catch(Exception e){e.printStackTrace ();} |-Rg].  
} =$bJ`GpJ  
} fP 1V1ao  
vTnrSNdSE  
Pdgn9  
//打印回应的头信息 3a9%djGq  
public void logResponseHead(HttpURLConnection con) 5)712b(&  
{ rP4v_?Zg+  
for(int i=1;;i++) nW)-bAV<  
{ =^liong0  
String header=con.getHeaderFieldKey(i); lMkDLobos  
if(header!=null) .CJQ]ECl7p  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xae0xs  
Utility.log(header+" : "+con.getHeaderField(header)); qHwHP 1  
else 'ec G:B`S  
break; (!b_o A8V  
} E :gS*tsY  
} w+A:]SU  
Skb,cKU  
5L ]TV\\  
public void splitterStop() 'XW[uK]w)  
{ >?Y)evW  
bStop = true; 05sWN0  
} t<~WDI|AN  
y{ & k`H  
:~uvxiF  
} Yz<,`w5/6~  
V+\L@mz;  
nP]tc  
/* Q?"o.T';  
**FileAccess.java IZ){xI  
*//文件访问(定位,写) JFOto,6L:  
package NetFox; :TU|;(p  
import java.io.*; #+VH]7]  
yf|,/{S  
G.j  R  
public class FileAccessI implements Serializable{ g/*x;d=  
m(2(Caz{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /"~ D(bw0=  
RandomAccessFile oSavedFile; GCrIa Z  
long nPos; 1 zo0/<dk  
3C:!\R  
^3>Qf  
public FileAccessI() throws IOException XOOWrK7O  
{ NxOiT#YH  
this("",0); euxkw]`h6  
} hbZ]DRg  
Qu 7#^%=  
)gX7qQ  
public FileAccessI(String sName,long nPos) throws IOException z@70{*  
{ 4}i2j  
oSavedFile = new RandomAccessFile(sName,"rw"); SW94(4qo  
this.nPos = nPos; LwPZRE#  
oSavedFile.seek(nPos); fj 14'T  
} [_$r-FA  
,(1n(FZ  
l ~bjNhk  
public synchronized int write(byte[] b,int nStart,int nLen) )7X+T'?%  
{ B: '}SA{  
int n = -1; ~Onj| w7  
try{ 72i ]`   
oSavedFile.write(b,nStart,nLen); -|1H-[Y(  
n = nLen; w@K4u{|  
} f+ }Rj0A  
catch(IOException e) ;HKb  
{ 4blw9x N  
e.printStackTrace (); It5U=PU  
} M lv  
iTX:*$~I  
1\'?.  
return n; R1!F mZW8  
} ;f]p`!] 3  
^A&i$RRO  
jwP}{mi*  
} {"^LUw8fd  
q+j.)e  
g]fdsZv  
/* uq/z.m  
**SiteInfoBean.java m7dpr$J  
*/ `5HFRgL`.  
package NetFox; 0n FEPMO  
^Vbx9UN/  
!b !C+ \v  
public class SiteInfoBean { qcNu9Ih  
Ou26QoT9XI  
i146@<\G{P  
private String sSiteURL; //Site's URL L9lNAiOH  
private String sFilePath; //Saved File's Path |*G$ilu  
private String sFileName; //Saved File's Name dz3KBiq  
private int nSplitter; //Count of Splited Downloading File xH,D bAC;  
2&e2/KEWR  
RFsd/K;Zp  
public SiteInfoBean() [RAzKzC\M  
{//nSplitter的缺省值为5 Fi7G S;  
//default value of nSplitter is 5 'zRi ;:UHA  
this("","","",5); $ 8"we  
} a\K__NCrX  
jY~W*  
Z.4 vKO[<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a&sVcsX  
{ "w PA;4VQ  
sSiteURL= sURL; miWPLnw=L  
sFilePath = sPath; :,<G6"i  
sFileName = sName; sI M^e  
this.nSplitter = nSpiltter; S!LLC{  
|b BA0.yS  
4qd =]i  
} )td?t.4  
 |UudP?E  
$0kuR!U.N  
public String getSSiteURL() qdM=}lbc  
{ gs xT  
return sSiteURL; Q3@MRR^tY  
} X0QY:?  
!!{!T;)l  
f1Z  
public void setSSiteURL(String value) LTn@OhC  
{ %^`b)   
sSiteURL = value; ^~p^N <  
} {6y@;Fd  
@;6I94Bp  
3Y;<Q>roT  
public String getSFilePath() 9_$i.@L 1  
{ T%[&[8{8  
return sFilePath; yLC5S3^1\"  
} bOB<m4  
1WTDF  
eX{:&Do  
public void setSFilePath(String value) B4&K2;fg_  
{ tRUGgf`  
sFilePath = value; ?(t{VdZSzQ  
} t PJW|wo  
H3}eFl=i2  
hJ)\Vo  
public String getSFileName() 7EfLd+  
{ JU6PBY~C'  
return sFileName; {vp|f~}zTw  
} A`#/:O4|f  
7Gos-_s  
b0PQ;?R#V  
public void setSFileName(String value) wt@Qjbqd8  
{ %',bCd{QW  
sFileName = value; A"Prgf eT  
} Fm{/&U^  
4s:S_Dw  
@|=JXSr!KY  
public int getNSplitter() X\=m  
{ ]-rhc.Gk@1  
return nSplitter; ,k9@%{4 l  
} EMTAl;P  
MV(Sb:RZ  
vqeWt[W v  
public void setNSplitter(int nCount) XEUy,>mR  
{ S-5|t]LV  
nSplitter = nCount; $ ]fautQlt  
} F0D7+-9[  
} J{69iQ  
Yn~N;VUA  
RaT_5PH~g  
/* hja;d1yH  
**Utility.java kPuI'EPK  
*/ ~Z{IdE  
package NetFox; ( !THd  
'Nqa=_<WW  
E7CeE6U  
public class Utility { I6.!0.G  
(V06cb*42[  
7\T~K Yb?  
public Utility() hx5oTJR  
{ YKWiZ  
z{>p<)h  
9B&fEmgEc?  
} 3IlflXb  
en5sqKqh+  
//线程睡眠 >RTmfV  
public static void sleep(int nSecond) l>kREfHq!{  
{ v/s6!3pnl  
try{ b3vPGR  
Thread.sleep(nSecond); fOHgz ,x=  
} j "^V?e5  
catch(Exception e) 2!Gb4V  
{ NI%&Xhn!*>  
e.printStackTrace (); Cj +{%^#  
} H}p5qW.tH:  
} &Q>tV+*  
k^%Kw(/  
//日志 fqY; > Z  
public static void log(String sMsg) `w;8xD(  
{ 1Z$` }a  
System.err.println(sMsg); 8M~^/Zc  
} }~akVh`3  
ov9+6'zya  
VJf|r#2  
public static void log(int sMsg) Uc[ @]  
{ ?x\tE]  
System.err.println(sMsg); 8NUVHcB6  
} d41DcgG'j(  
} m 4r!Ck|  
q b[UA5S\`  
2C &G' @>  
/* AWG;G+  
**TestMethod.java O'i!}$=g  
*/ -,Oq=w*EV  
package NetFox; U?[_ d  
J?1U'/Wx2  
"J_#6q*  
public class TestMethod { p!_3j^"{  
x Ilo@W6  
1[ 4)Sq?  
public TestMethod() q; n  
{ ///xx/weblogic60b2_win.exe g2|qGfl{C  
try{ kgl7l?|O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &| guPZ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A#@9|3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pc:5*H  
fileFetch.start(); qx;8Hq(E[  
} )[]*Y]vSx  
catch(Exception e){e.printStackTrace ();} `alQmGUZ  
..=WG@>$+  
c(j|xQ\pE  
} 2x<A7l)6  
937 z*mh  
Ht,dMt>:  
public static void main(String[] args) hh1 ?/  
{ |l#<vw wE  
new TestMethod(); \$B%TY  
} yd>b2 M  
} +! F+m V9  
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