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http断点续传简单实现(java)

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/* gHrs|6q9  
**SiteFileFetch.java f +{=##'0  
*/ gwRB6m$  
package NetFox; <46&R[17M  
import java.io.*; FklR!*oL,)  
import java.net.*; i}sAF/  
G`Nw]_ Z_  
m9DFnk<D  
public class SiteFileFetch extends Thread { }kqh[`:  
,PTM'O@aU#  
* 9^8NY]  
SiteInfoBean siteInfoBean = null; //文件信息Bean ahg:mlaob  
long[] nStartPos; //开始位置 A'DFY {  
long[] nEndPos; //结束位置 I)Xf4F S@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 E1eGZ&&Gd  
long nFileLength; //文件长度 CO='[1"_5  
boolean bFirst = true; //是否第一次取文件 g Ed A hfx  
boolean bStop = false; //停止标志 tQ|c.`)W  
File tmpFile; //文件下载的临时信息 olE(#}7V  
DataOutputStream output; //输出到文件的输出流 u ]e-IYH  
OlOOg  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) i/x |c!E  
public SiteFileFetch(SiteInfoBean bean) throws IOException )4L2&e`k)(  
{ p"ZvA^d\   
siteInfoBean = bean; nF<K84  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); uL`#@nI  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); SIJ7Y{\.  
if(tmpFile.exists ()) QnWE;zN[7A  
{ mgAjD.  
bFirst = false; yYA*5 7^A  
read_nPos(); V`^*Z}d9  
} ,t9EL 21  
else @N4_){s*  
{ ws'e  
nStartPos = new long[bean.getNSplitter()]; SK}sf9gTv  
nEndPos = new long[bean.getNSplitter()]; tOiz tYu  
} .SD-6GVD  
.\R9tt}  
h0tiWHw  
PR%)3  
} )@NFV*@I  
MJXnAIG?2  
6]brL.eGj  
public void run() MXaF q K<Y  
{ vB8$Qx\J  
//获得文件长度 ,|A^ <R`  
//分割文件 SGWb*grt  
//实例FileSplitterFetch ]<;7ZNG"Y5  
//启动FileSplitterFetch线程 _z@/~M(  
//等待子线程返回 msBoInhI  
try{ MzIDeZ  
if(bFirst) EN!C5/M{&  
{ 41X`.  
nFileLength = getFileSize(); 1<r!9x9G  
if(nFileLength == -1) V~*Gk!+f  
{ gk%nF  
System.err.println("File Length is not known!"); dk|LC-]`A  
}  XIInI  
else if(nFileLength == -2) 7;EDU  
{ qUJ"* )S  
System.err.println("File is not access!"); ;g0Q_F@;p  
} Q,3kaR@O  
else W%L'nR~w$  
{ wQ+pVu?6_  
for(int i=0;i<nStartPos.length;i++) ,1sbY!&ekL  
{ >v+1 v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Hr?lRaV  
} A8'RM F1  
for(int i=0;i<nEndPos.length-1;i++) sFpg  
{ FRQ.ix2  
nEndPos = nStartPos[i+1]; )U %`7(bN  
} ?'> .>  
nEndPos[nEndPos.length-1] = nFileLength; rN}pi@  
} & kC  
} /~NX<Ye&  
g04^M (  
(47?lw &  
//启动子线程 \CjJa(vV  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w}3N!jNDv  
for(int i=0;i<nStartPos.length;i++) X _ZO)|  
{ D6bYg `  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R-Edht|{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), syl7i>P  
nStartPos,nEndPos,i); W.j^L;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _k@cs^  
fileSplitterFetch.start(); $JY \q2  
} [7I:Dm  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d A)T>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jFN0xGZ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wn[)/*(,$(  
nEndPos = " + nFileLength); L$PbC!1  
// fileSplitterFetch[nPos.length-1].start(); `+,?%W)  
L`nW&; w'  
a=MN:s?Fc0  
//等待子线程结束  0s;~9>  
//int count = 0; ;Nn(  
//是否结束while循环 v9f+ {Y%-  
boolean breakWhile = false; jEBn"]\D  
dmF=8nff  
q;e b  
while(!bStop) #/YS  
{ \!^=~` X-  
write_nPos(); apL$`{>US  
Utility.sleep(500); aO1^>hy  
breakWhile = true; |Hf|N$  
lh;fqn`  
K#OL/2^ 5  
for(int i=0;i<nStartPos.length;i++) FyEKqYl  
{ Yi Zk|K_  
if(!fileSplitterFetch.bDownOver) m9[ 7"I  
{ nah?V" ?Y  
breakWhile = false; ,WyEwc]  
break; ._rPM>B?  
} '4'Z  
} mx9vjW fy  
if(breakWhile) s@Q7F{z  
break; p"0#G&-  
c,1  G+.  
}b2YX+/e$f  
//count++; 0nt@}\j  
//if(count>4) }b1G21Dc!  
// siteStop(); !>9s  
} pT,8E(*l2  
(_pw\zk>  
g (w/  
System.err.println("文件下载结束!"); ?'k_K:_  
} beO Mln+R  
catch(Exception e){e.printStackTrace ();} &PC6C<<f  
} }d%CZnY&7  
V lx.C~WYn  
/h53;$zK  
//获得文件长度 "l&SRX?g  
public long getFileSize() V|YQhd0kv  
{ 89M'klZ   
int nFileLength = -1; Q/|.=:~FO  
try{ FAM{p=t]HT  
URL url = new URL(siteInfoBean.getSSiteURL()); Au2?f~#Fv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Htgo=7!?\3  
httpConnection.setRequestProperty("User-Agent","NetFox"); B{/og*xd*1  
UBL{3s^"  
Z1fY' f  
int responseCode=httpConnection.getResponseCode(); F~Dof({:  
if(responseCode>=400) GQ1/pys  
{ e=&~6bs1U  
processErrorCode(responseCode); BH'*I yv  
return -2; //-2 represent access is error ~v8X>XDL?T  
} h3`}{ w  
,>B11Z}PH  
?|ZbQz(bL  
String sHeader; Ck/44Wfej  
GFFwk4n1  
7^i7U-A<A  
for(int i=1;;i++) {~9zuNi  
{ $NR[U+  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xb\EJ1M>  
//Utility.log(in.readLine()); ]T)N{"&N/  
sHeader=httpConnection.getHeaderFieldKey(i); HO<|EH~lu  
if(sHeader!=null) I(M/ X/  
{ kN/YnY*J<  
if(sHeader.equals("Content-Length")) KJ+6Y9b1  
{ 6 /<Hx@r (  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0d+n[Go+S  
break; f&CQn.K"  
} T U6s~  
} >5t! Xt  
else 1 iox0  
break; 3@" :&  
} AUD) =a>  
} ,P9F*;Dj  
catch(IOException e){e.printStackTrace ();} lrJV"H  
catch(Exception e){e.printStackTrace ();} Pm%xX~H  
fnq 3ic"V  
ZiZ@3O6  
Utility.log(nFileLength); 3t<a3"{9  
]$ d ;P  
L(|K{vHh]  
return nFileLength; 1Le8W)J  
} e:HORc~U  
i+14!LlI  
\a+Q5g  
//保存下载信息(文件指针位置) 8-@@QZ\N  
private void write_nPos() YC1Bgz  
{ AO5&Y.A#  
try{ |tAkv  
output = new DataOutputStream(new FileOutputStream(tmpFile)); P;.roD9  
output.writeInt(nStartPos.length); s4|tWfZ  
for(int i=0;i<nStartPos.length;i++) 9`Qa/Y!  
{ :!_l@=l  
// output.writeLong(nPos); 8gavcsVE[  
output.writeLong(fileSplitterFetch.nStartPos); 0U7Gl9~  
output.writeLong(fileSplitterFetch.nEndPos); .F,l>wUNe  
} ^'=[+  
output.close(); ;j9%D`u<  
} (m'-1wX.  
catch(IOException e){e.printStackTrace ();} I/w;4!+)  
catch(Exception e){e.printStackTrace ();} }K?b2 6`  
} r[(;J0=  
6?u`u t  
 +rv##Z  
//读取保存的下载信息(文件指针位置) |m KohV qr  
private void read_nPos() LF7 }gQs ^  
{ l :{q I#Q  
try{ =6U5^+|d  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x1Gx9z9  
int nCount = input.readInt(); 2OUx@Vj  
nStartPos = new long[nCount]; dm}1"BU<  
nEndPos = new long[nCount]; lW5Lwyt8  
for(int i=0;i<nStartPos.length;i++) sl-wNIQ  
{ ]r#b:W\  
nStartPos = input.readLong(); D9TjjA|zS  
nEndPos = input.readLong(); Ja~8ZrcY  
} ; =n}61  
input.close(); ho$}#o  
} HWV A5E[`Y  
catch(IOException e){e.printStackTrace ();} ogIu\kiZ  
catch(Exception e){e.printStackTrace ();} EmaS/]X[  
} -r,v3n  
[s$x"Ex  
6/ 5c|  
private void processErrorCode(int nErrorCode) nl}LT/N  
{ "*HM8\  
System.err.println("Error Code : " + nErrorCode); :|9vMM^$  
} 0 7Yak<+~  
)Wle CS_  
R]yce2w"z  
//停止文件下载 R ?s;L r  
public void siteStop() 2FZ T  
{ S!PG7hK2  
bStop = true; rGQD+ d  
for(int i=0;i<nStartPos.length;i++) >TglX t+  
fileSplitterFetch.splitterStop(); F m:Ys](  
hqln6m  
Qw5-/p=t  
} Xps \+l%i  
} YZ<z lU  
//负责部分文件的抓取 qeFaY74S  
**FileSplitterFetch.java 6~sU[thGW  
*/ M @KQOAzt  
package NetFox; +F q_w  
rrz([2E2  
l7uTk5  
import java.io.*; `Njvk  
import java.net.*; YCE *Dm  
zgz!"knVx  
j_d}?jh  
public class FileSplitterFetch extends Thread { p>eYi \'  
p@O Ip  
uDND o  
String sURL; //File URL Ce-= -  
long nStartPos; //File Snippet Start Position }'tJc $!  
long nEndPos; //File Snippet End Position |J4sQ!%K  
int nThreadID; //Thread's ID g4k3~,=D3  
boolean bDownOver = false; //Downing is over Y!45Kio  
boolean bStop = false; //Stop identical q)9n%- YgP  
FileAccessI fileAccessI = null; //File Access interface %\HE1d5;  
fZpi+I  
J:"@S%gy%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q>Klkd5(  
{ /&|p7  
this.sURL = sURL; tl /i  
this.nStartPos = nStart; Odwf7>  
this.nEndPos = nEnd; 9QX!HQ|5y8  
nThreadID = id; 'k]~Q{K$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eYP^.U)  
} 3O; H&  
1K#[Ef4  
OqS!y( (  
public void run() im9 w|P5  
{ Eoixw8hz  
while(nStartPos < nEndPos && !bStop) 1#c Tk  
{ qE2VUEv5Y  
pTGGJ,  
UapU:>!"`  
try{ VqvjOeCbH  
URL url = new URL(sURL); } r(b:}DN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;^bfLSWm{  
httpConnection.setRequestProperty("User-Agent","NetFox"); @gb W:  
String sProperty = "bytes="+nStartPos+"-"; IV!`~\@  
httpConnection.setRequestProperty("RANGE",sProperty); a9;KS>~bq  
Utility.log(sProperty); [uGsF0#e  
T8Mqu`$r  
l0^cdl-  
InputStream input = httpConnection.getInputStream(); ,vmn{gz  
//logResponseHead(httpConnection); LDEc}XXb  
~b*]jZwT  
/0qbRk i  
byte[] b = new byte[1024]; p~3 x=X4  
int nRead; 0ZwXuq  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k L6s49  
{ /d}"s.3p  
nStartPos += fileAccessI.write(b,0,nRead); +kd1q  
//if(nThreadID == 1) I;"pPJ3G  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nc(CGl:  
} mST8+R@S  
Lhp&RGy  
[u!n=ev  
Utility.log("Thread " + nThreadID + " is over!"); ?2#'>B  
bDownOver = true; y>w;'QR&a  
//nPos = fileAccessI.write (b,0,nRead); 2? yo  
} Z@dVK`nD  
catch(Exception e){e.printStackTrace ();} \8$~ i  
} j24 3oD  
} mrRid}2  
izcaWt3 a  
XX /s@C  
//打印回应的头信息 -t S\  
public void logResponseHead(HttpURLConnection con) UJh;Hp:  
{ B VeMV4  
for(int i=1;;i++) `dcz9 *  
{ }R 16WY_'  
String header=con.getHeaderFieldKey(i); ;6``t+]q   
if(header!=null) Z6${nUX  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ur]$@N  
Utility.log(header+" : "+con.getHeaderField(header)); #0T/^ #  
else FHU6o910  
break; L~t< 0\r  
} hZHM5J~  
} ";=!PL  
DqQ p47kp  
_rB,N#{2R=  
public void splitterStop() -->0e{y  
{ CnL=s6XD'  
bStop = true; H}kSXKO8!8  
} MuOKauYa  
3%?tUt  
tXtNK2-1  
} 8O]`3oa>  
T 'c39  
g|]HS4y  
/* \Aro Sy9  
**FileAccess.java l[:Aq&[o3  
*//文件访问(定位,写) $4xSI"+M%  
package NetFox; aA#79LS  
import java.io.*; ~5&4s  
1b1Ab zN  
rWL;pM<  
public class FileAccessI implements Serializable{  iiQn/%  
_xv3UzD  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 exhU!p8  
RandomAccessFile oSavedFile; @T\n@M]  
long nPos; X8ap   
b v_ UroTr  
j~{cT/5Y_  
public FileAccessI() throws IOException h97#(_wV>  
{ a)ry}E =f  
this("",0); 4{F1GW  
} Kb(11$U  
edo)W mn  
A_9^S!  
public FileAccessI(String sName,long nPos) throws IOException ]S&ki}i&  
{ Su,:f_If,  
oSavedFile = new RandomAccessFile(sName,"rw"); 1`7zYW&L  
this.nPos = nPos; "QdK Md  
oSavedFile.seek(nPos); To>,8E+GAb  
} nte?a e  
K#Ck,Y"  
XJe=+_K9  
public synchronized int write(byte[] b,int nStart,int nLen) ffmtTJFC5  
{  eo9/  
int n = -1; q_.fVn:!  
try{ d:';s~  
oSavedFile.write(b,nStart,nLen); sRD fA4/TF  
n = nLen; _aPAn|.  
} =lJ ?yuc  
catch(IOException e) @M"gEeI9  
{ )k,n}  
e.printStackTrace (); DSz[,AaR]  
} 7tcadXk0  
-Ty~lZ)TDT  
!} TsFa  
return n; kh0cJE\_^  
} 4uIYX  
EpAgKzVpJ  
Z71m(//*}  
} D|9+:Y  
*(Dmd$|0|  
u)0I$Tc"  
/* _h!.gZB3  
**SiteInfoBean.java 7l69SQo]?  
*/ 3{3@>8{w  
package NetFox; gY~r{  
GjhTF|  
|[>@Kk4  
public class SiteInfoBean { 0MHiW=  
:ZrJL&  
T-%=tY+-  
private String sSiteURL; //Site's URL Eu?z!  
private String sFilePath; //Saved File's Path X@`a_XAfd  
private String sFileName; //Saved File's Name (P)G|2=  
private int nSplitter; //Count of Splited Downloading File Q|AZv>'!  
27eG8  
>u$8Z  
public SiteInfoBean() Tzex\]fw  
{//nSplitter的缺省值为5 -)}s{[]d6m  
//default value of nSplitter is 5 sE"s!s/  
this("","","",5); :k/Xt$`  
} 2 kDsIEA  
`} PYltW  
7s(tAbPdB  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 92DM1~ *  
{ ss)x fG  
sSiteURL= sURL; f4f2xe7\Q  
sFilePath = sPath; _B^zm-}8|B  
sFileName = sName; ~18a&T:  
this.nSplitter = nSpiltter; .hat!Tt9  
C{}_Rb'x  
@V*dF|# /  
} q\6(_U#Tl  
D`LBv,n  
B3#G  
public String getSSiteURL() !K>iSF<  
{ KMRPleF  
return sSiteURL; =5+*TL`  
} sasurR|;  
6z9 '|;,4  
TQ4@|S:OF  
public void setSSiteURL(String value) {6'X z  
{ 7PY$=L48A  
sSiteURL = value; !__0Vk[s  
} [%P#ieD4  
#V!a<w4_  
KrE 'M  
public String getSFilePath() ntW@Fm:bw>  
{ 9|+6@6VY!  
return sFilePath; mOE *[S)  
} 3"y 6|e/5  
! xCo{U=  
UD.b b  
public void setSFilePath(String value) r`O Yq  
{ 75^6?#GS  
sFilePath = value; W:d p(,L  
} A'|!O:s   
BN_h3|)  
|9I)YD  
public String getSFileName() [oLV,O|s|j  
{ ^po@U"  
return sFileName; gF)9a_R%p  
} [qYr~:`-[  
5>x_G#W  
ffrIi',@  
public void setSFileName(String value) {OU|'  
{ {a7~P0$  
sFileName = value; x e`^)2z  
} vi,hWz8WB  
Y?0/f[Ax,y  
$coO~qvU  
public int getNSplitter() X,QsE{  
{ ,;)ZF  
return nSplitter; J Wn26,  
} q A)O kR'm  
cr1x CPJj  
 ?%,NOX  
public void setNSplitter(int nCount) *G19fJ[5  
{ = S&`~+  
nSplitter = nCount; C?<pD+]b_  
} Q.mJ7T~T  
} f O*jCl  
q-F K=r 5  
4qQ,1&!]S  
/* G7%bY  
**Utility.java gYKz,$  
*/ 2B,O/3y  
package NetFox; Ed9Uw 7  
/A=w`[<  
6%v9o?:~l  
public class Utility { -=ZL(r 1  
.G0 N+)  
Luq4q95]  
public Utility() a{5SOe;;  
{ #z `W ,^C  
,erw(7}'.  
;5[KZ8j6Y  
} 8H!QekQZ]\  
 F!omkN  
//线程睡眠 `9~ %6N?7#  
public static void sleep(int nSecond) ,WT>"9+  
{ }Z!D?(  
try{ %q{q.(M#  
Thread.sleep(nSecond); d1 j9{  
} 2QfN.<[-  
catch(Exception e) drq3=2  
{ ]R__$fl`8  
e.printStackTrace (); kx"1 0Vw  
} &.?XntI9O  
} m~=~DMj  
$<}c[Nm  
//日志 #~u0R>=  
public static void log(String sMsg) LFp "Waiv  
{ +{J8,^z#  
System.err.println(sMsg); )- C3z   
} 0 'QWa{dS\  
P15 H[<:Fz  
CD|[PkjW  
public static void log(int sMsg) "LMj,qZ1!  
{ %`Re {%1;  
System.err.println(sMsg); 4fEDg{T  
} }cKB)N BJb  
} pfA6?tP`  
zw0w."V  
XX6Z|Y5.  
/* 7>vm?a^D2&  
**TestMethod.java #&Sr;hAJ  
*/ X#B b?Pv  
package NetFox; :=*de Z<  
9"[;ld<  
v9*m0|T0M  
public class TestMethod { &p0e)o~Ux  
/ HTY>b  
}f}.>B0#  
public TestMethod() _7 3q,3`24  
{ ///xx/weblogic60b2_win.exe ?6#won  
try{ d=!:UB  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gq?:n.;TY  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +6m.f,14q  
SiteFileFetch fileFetch = new SiteFileFetch(bean); QTV*m>D  
fileFetch.start(); .n-#A  
} y8Va>ul"U  
catch(Exception e){e.printStackTrace ();} 7R+(3NU1A  
6b|?@  
G#M)5'Q]U  
}  C0rf  
!40>LpL[  
/zn=AAYb  
public static void main(String[] args) o5<<vvdA  
{ ~(5r+Z}*`  
new TestMethod(); k9|5TLXq?  
} ]I*c:(qwu  
} `?Rq44=  
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