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http断点续传简单实现(java)

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/* lY9M<8g  
**SiteFileFetch.java ikG9l&n  
*/ 4eL54).1O  
package NetFox; 1"B9Z6jf  
import java.io.*; @ZR4%A"X4  
import java.net.*; UH&1c8y}  
rRrW   
mW0&uSM D  
public class SiteFileFetch extends Thread { ieRBD6_  
;}jbdS3  
tSc>@Q_|  
SiteInfoBean siteInfoBean = null; //文件信息Bean <ZC^H  
long[] nStartPos; //开始位置 &t|V:_?/x  
long[] nEndPos; //结束位置 AYu'ptDNr  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !2U7gVt"*  
long nFileLength; //文件长度 Mth`s{sATa  
boolean bFirst = true; //是否第一次取文件 @j2*.ee  
boolean bStop = false; //停止标志 HT=Am  
File tmpFile; //文件下载的临时信息 Yn]y d1  
DataOutputStream output; //输出到文件的输出流 P| P fG=  
Iki+5  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ) a\DS yr  
public SiteFileFetch(SiteInfoBean bean) throws IOException #0<y0uJ(y  
{ _.*4Y  
siteInfoBean = bean; :Z]hI+7  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~7 L)n  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); UEQ'D9  
if(tmpFile.exists ()) r]O@HVbt$  
{ {e[pSD6   
bFirst = false; AH 87UkNL  
read_nPos(); = *;Xc-_  
} w$[Ds  
else |U$de2LF  
{ ?"<r9S|[O  
nStartPos = new long[bean.getNSplitter()]; uC*:#[  
nEndPos = new long[bean.getNSplitter()]; ^r$iN %&~  
} ""v`0OP&J  
c]!D`FA*K  
Q @OC=  
vV\F^  
} -,fa{yt-  
a.&#dxgW[  
$X=D9h  
public void run() ctUF/[_w;  
{ _ kSPUP5  
//获得文件长度 +V+*7s%fL  
//分割文件 r~G]2*3  
//实例FileSplitterFetch h[ZN >T  
//启动FileSplitterFetch线程 A;WwS?fyQ  
//等待子线程返回 [T[9*6Kt  
try{ 6:@t=C  
if(bFirst)  e(;`9T  
{ CX ]\Q-y  
nFileLength = getFileSize();  2H K  
if(nFileLength == -1) kGuk -P  
{ $sL|'ZMbS  
System.err.println("File Length is not known!"); q>|[JJ*6_N  
} & A9A#It  
else if(nFileLength == -2) #C,f/PXfaB  
{ bu"68A;>  
System.err.println("File is not access!"); ic0v*Y$  
} IL>/PuZku  
else ,F`KQ )\"  
{ |`Oa/\U  
for(int i=0;i<nStartPos.length;i++) Y9@dZw%2  
{ ?y*+^E0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6`4W,  
} Y zBA{FE  
for(int i=0;i<nEndPos.length-1;i++) /@:up+$  
{ nc\C 4g  
nEndPos = nStartPos[i+1]; ? __aVQ7  
} d7_g u  
nEndPos[nEndPos.length-1] = nFileLength; VM]GYz|#]  
} N{hF [F  
} *e-ptgO  
,y8I)+  
<jRFN&"h}  
//启动子线程 6mF{ImbRbS  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {r].SrW9s9  
for(int i=0;i<nStartPos.length;i++) mj(&`HRs4  
{ Mi/ &$" =  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]Ic?:lKN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V^`?8P8d  
nStartPos,nEndPos,i); (+gL#/u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |:(23O  
fileSplitterFetch.start(); :B*vkwT  
} ^QXw[th!d  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zOiY0`=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Rgfc29(8  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =,C9O  
nEndPos = " + nFileLength); D-o7yc"K  
// fileSplitterFetch[nPos.length-1].start(); 8R)D! 7[l  
3m43nJ.~  
"'F;lzq  
//等待子线程结束 0Y6q$h>4  
//int count = 0; gP %|:"  
//是否结束while循环 DD@)z0W  
boolean breakWhile = false; O+E1M=R6h  
S}m$,<x  
1(%>`=R8  
while(!bStop) @Ge>i5q  
{ oxMUW<gYd  
write_nPos(); aW=By)S!Y  
Utility.sleep(500); PHRGhKJW})  
breakWhile = true; 9b"9m*gC  
`s>UU- 9  
4{*tn"y  
for(int i=0;i<nStartPos.length;i++) |ilv|UV  
{ L8bI0a]r"*  
if(!fileSplitterFetch.bDownOver) OBI+<2`Oc  
{ 7ZV~op2Q  
breakWhile = false; up3?$hUc.  
break; T}n}.JwU  
} J+}+ "h~.  
} {ywXz|TP  
if(breakWhile) (@KoqwVWc  
break; o9m  
tIGVB+g{F  
w\o)bn  
//count++; + %MO7vL  
//if(count>4) d`9W  
// siteStop(); pwFU2}I  
} FpdDIa  
]3O 4\o  
Wa[x`:cT?u  
System.err.println("文件下载结束!"); e~+(7_2  
} f=:3!k,S  
catch(Exception e){e.printStackTrace ();} KMK&[E#r  
} IU Y> ih  
:H!(?(Pie  
@,x_i8  
//获得文件长度 6%gB E  
public long getFileSize() E\]OySC%C$  
{  Y8)E]D  
int nFileLength = -1; MvFM ,  
try{ J$#h( D%  
URL url = new URL(siteInfoBean.getSSiteURL()); {J,6iP{>ZN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a>wfhmr  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]UX`=+{  
. ]o3A8  
2E`~ qn  
int responseCode=httpConnection.getResponseCode(); \!+-4,CbZY  
if(responseCode>=400) [ME}Cv`?<E  
{ u\{qH!?t  
processErrorCode(responseCode); ]Q6+e(:~ZH  
return -2; //-2 represent access is error I#|ocz  
} .q0218l:dF  
;YK!EMM4!h  
Aautih@LX  
String sHeader; Q'Jv} 'eK_  
Ni2]6U  
H+4=|mkQ  
for(int i=1;;i++) {8^Gs^c c  
{ <u/a`E?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _4P;+Y  
//Utility.log(in.readLine()); U/T4i#  
sHeader=httpConnection.getHeaderFieldKey(i); xT9Yes&  
if(sHeader!=null) ''#p47$8<d  
{ ?mH@`c,fM  
if(sHeader.equals("Content-Length")) ],;D2]<s  
{ 5/& 1Oxo  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `%-4>jI9-  
break; Y]C; T  
} hc-lzYS  
} /635B*g  
else r1i$D  
break; `IEq@Wr#$!  
} 79)A%@YHQQ  
} ;yF[2P ;  
catch(IOException e){e.printStackTrace ();} 0o=!j3RjH  
catch(Exception e){e.printStackTrace ();} cu[!D}tVU  
5^)?mA  
#v.L$7O  
Utility.log(nFileLength); \'n$&PFe  
X'cf&>h  
u-m%=2  
return nFileLength; Q`H# fS~  
} '5'3_vM  
w[ Axs8N'  
mfXD1]<.  
//保存下载信息(文件指针位置) `.{U-U\  
private void write_nPos() ; D1FAz  
{ 5a'yXB}  
try{ hP?7zz$*j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); WK pUn8&N  
output.writeInt(nStartPos.length); /&CUspb  
for(int i=0;i<nStartPos.length;i++) CV'&4oq  
{ *"1~bPl  
// output.writeLong(nPos); ; ;<J x.  
output.writeLong(fileSplitterFetch.nStartPos); l`SK*Bm~<  
output.writeLong(fileSplitterFetch.nEndPos); ./$ <J6-J  
} q1H=/[a  
output.close(); 53B.2 4Tm  
} S[v Rw]*  
catch(IOException e){e.printStackTrace ();} JW=uK$sO  
catch(Exception e){e.printStackTrace ();} Yt -W1vl  
} @4;&hP2Z:  
@gNpJB]V  
~eDI$IO  
//读取保存的下载信息(文件指针位置) K} +S+ *_  
private void read_nPos() 5N\+@grp  
{ 8KFj<N>'  
try{ {={^6@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P3G:th@j=  
int nCount = input.readInt(); sp|q((z{  
nStartPos = new long[nCount]; +9RJ%i&Ec  
nEndPos = new long[nCount]; =M/qV  
for(int i=0;i<nStartPos.length;i++) : (cb2j(C  
{ :3v9h^|+  
nStartPos = input.readLong(); <nBo}0O}  
nEndPos = input.readLong(); PNf&@  
} Y+FP   
input.close(); qYx!jA]O  
} @|DmE!)  
catch(IOException e){e.printStackTrace ();} pjACFVMFX  
catch(Exception e){e.printStackTrace ();} zt?h^zf}  
} 0A.PD rM:  
_ j~4+H  
oew|23Ytb  
private void processErrorCode(int nErrorCode) qmEoqU  
{ z OtkC3hY  
System.err.println("Error Code : " + nErrorCode); f3 !n$lj  
} _74UdD{^o  
m=H_?W;  
Vn'?3Eb<  
//停止文件下载 P@C c]Z  
public void siteStop() `mrCu>7  
{ |"Z-7@/k$i  
bStop = true; D ZVXz|g  
for(int i=0;i<nStartPos.length;i++) 3)Zu[c[%'J  
fileSplitterFetch.splitterStop(); Vb2\/e:k  
ZW>o5x__b  
4Q;<Q"  
} Lx%:t YZ  
} HcA[QBh  
//负责部分文件的抓取 [<yz)<<  
**FileSplitterFetch.java PB+\jj  
*/ 5C B%=iL{  
package NetFox; g92dw<$>  
Hq?&Qo  
yxvjg\!&  
import java.io.*; PcB{ = L  
import java.net.*; 0(8gQ 2n  
DcN"=Y  
'j}g  
public class FileSplitterFetch extends Thread { ehE-SrkU'  
-,^WaB7u\  
%*jGim~s  
String sURL; //File URL : W~f;k  
long nStartPos; //File Snippet Start Position eES'}[W>  
long nEndPos; //File Snippet End Position as(*B-_n~  
int nThreadID; //Thread's ID jn^fgH ?  
boolean bDownOver = false; //Downing is over Oxv+1Ub<Dv  
boolean bStop = false; //Stop identical G,]z (%  
FileAccessI fileAccessI = null; //File Access interface bE d?^h  
zks#EzQ  
;, rnk-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@ZoV  
{ /ERNS/w  
this.sURL = sURL; !R74J=#(  
this.nStartPos = nStart; ?I[h~vr6.  
this.nEndPos = nEnd; ^!}F%  
nThreadID = id;  i S  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ihg~Q4t  
} VHW`NP 5Jl  
,E?4f @|X  
.fEw k  
public void run() Ukc'?p,*  
{ jn$j^ 51`C  
while(nStartPos < nEndPos && !bStop) wWTQ6~Y%d  
{ #/ +I*B*y  
y@3kU*-1  
akC>s8tqlA  
try{ )Oievu_"|  
URL url = new URL(sURL); b+Vi3V  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @h#Xix7  
httpConnection.setRequestProperty("User-Agent","NetFox"); i=L8=8B`  
String sProperty = "bytes="+nStartPos+"-"; 1"O&40l  
httpConnection.setRequestProperty("RANGE",sProperty); 4)^vMG&  
Utility.log(sProperty); RL*]g*  
TT7PQf >  
 P?J kP  
InputStream input = httpConnection.getInputStream(); /PqUXF  
//logResponseHead(httpConnection); :G 5C ]'t  
6R2uWv  
4%7s259%  
byte[] b = new byte[1024]; 4.Z(:g  
int nRead; ~^$MA$/p  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g\&2s,  
{ =Z`0>R`  
nStartPos += fileAccessI.write(b,0,nRead); >A($8=+#x  
//if(nThreadID == 1) U Du~2%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HN68!v}C|  
} cy3M^_5B<  
fK_~lGY(  
;Iq5|rzDn  
Utility.log("Thread " + nThreadID + " is over!"); K_#UZA< Y  
bDownOver = true; uN bIX:L,  
//nPos = fileAccessI.write (b,0,nRead); {y6C0A*  
} 5 `=KyHi:b  
catch(Exception e){e.printStackTrace ();} t77'fm  
} &XQZs`41+  
} ltSh'w0  
S?4KC^Y5  
x: ~d@  
//打印回应的头信息 a5?A!k\2  
public void logResponseHead(HttpURLConnection con) B {aU;{1  
{ @9vvR7{P  
for(int i=1;;i++) tOH0IE c  
{ zMGzReJ  
String header=con.getHeaderFieldKey(i); >vVw!.fJ  
if(header!=null) -:S IS`0s  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); El (/em  
Utility.log(header+" : "+con.getHeaderField(header)); 8l23%iWxe  
else S+ebO/$>  
break; b_vTGl1_6  
} 3dG4pl~  
} %[ Zz0|A  
lzDdD3Ouc  
]"sRS`0+  
public void splitterStop() v[&'k\  
{ ,I`_F,  
bStop = true; tD-gc ''H  
} _whF^g8  
|<(t}}X  
Spgg+;9  
} B 8{ uR  
jczq `yW  
sRq U]i8l  
/* Pp*}R2  
**FileAccess.java ~@P)tl>  
*//文件访问(定位,写) j=ihbR^]Tl  
package NetFox; Q2c*.Y  
import java.io.*; N9]xJgTze  
4ht\&2&:  
WZ?!!   
public class FileAccessI implements Serializable{ 0H[LS  
T~J? AKx  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]l[2hy= cV  
RandomAccessFile oSavedFile; h|p[OecG  
long nPos; R 1'`F{56  
?N>pZR  
e{C6by"j{S  
public FileAccessI() throws IOException 2EfflZL3  
{ "HC)/)Mv@  
this("",0); c7qwNs*f  
} [ H,u)8)  
!8$RBD %  
 YqU/\f+  
public FileAccessI(String sName,long nPos) throws IOException maDz W_3  
{ *#2Rvt*Ox  
oSavedFile = new RandomAccessFile(sName,"rw"); O,mip  
this.nPos = nPos; Of`c`-<j  
oSavedFile.seek(nPos); ]k*1KP  
} ,4Y*:JU4  
[6R fS  
0x5xLg;Q  
public synchronized int write(byte[] b,int nStart,int nLen) o.^y1mH'  
{ 2U9&l1P=  
int n = -1; / Z!i;@Wf  
try{ El6bD% \G  
oSavedFile.write(b,nStart,nLen); V`k8j-*s  
n = nLen; r7I B{}>-  
} m:{tgcE  
catch(IOException e) 9+Nw/eszO  
{ irMd jG  
e.printStackTrace (); %MJ;Q?KB  
} 8#59iQl  
d+}kg  
(1){A8=?o  
return n; 3k' .(P|F  
} \L[i9m|e  
VPd,]]S5(  
n+oDC65[  
} <LA^%2jT  
( v@jc8y  
VJ{pN~_1  
/* SI*^f\lu  
**SiteInfoBean.java < y>:B}9'  
*/ \FifzKA  
package NetFox; DJP 6TFT&G  
{$fsS&aPg  
g-@h>$< 1  
public class SiteInfoBean { Nl*i5 io  
 r(`nt-o@  
7& 6Y  
private String sSiteURL; //Site's URL _/ Os^>R  
private String sFilePath; //Saved File's Path i&Kz*,pt  
private String sFileName; //Saved File's Name $(q8y/,R*-  
private int nSplitter; //Count of Splited Downloading File G;]:$J  
_N'75  
)|]Z>>%t  
public SiteInfoBean() )+Y&4Qu  
{//nSplitter的缺省值为5 hI~SAd ,#A  
//default value of nSplitter is 5 !k<:k "7  
this("","","",5); ]rW8y%yD  
} 7GZq|M_:y  
Z2p> n`D  
+t]Xj1Q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3s(Ia^  
{ v8@eW.I1  
sSiteURL= sURL;  @Fx@5e  
sFilePath = sPath; FA$zZs10\  
sFileName = sName; EOVZGZF  
this.nSplitter = nSpiltter; k dU! kj  
@]'S eiNp  
g%\L&}Jd  
} qm(1:iK,0  
1^{`lK~2  
._<ii2K'  
public String getSSiteURL() 40K2uT{cq  
{ <NB41/  
return sSiteURL; xmH-!Da  
} \G;CQV#{9  
7 g6RiH}  
59!)j>f  
public void setSSiteURL(String value) fLB1)kTS  
{ 77We;a  
sSiteURL = value; UR3$B%i  
} Alz~-hqQ  
@{}rG8  
3jPB#%F  
public String getSFilePath() >oqZ !V5[  
{ |9,UaA  
return sFilePath; Z> 74.r  
} p`>d7S>"  
QN G&  
*fhX*e8y  
public void setSFilePath(String value) _t-7$d"  
{ f a5]a  
sFilePath = value; OFy,B-`A{  
} +1@AGJU3  
=A n`D  
NWKi ()nA%  
public String getSFileName() :ba/W&-d  
{ eXzXd*$S  
return sFileName; '_o@V O  
} *not.2+  
V}9;eJRvw  
s4t0f_vj`  
public void setSFileName(String value) E`AYee%l  
{ 3N< & u   
sFileName = value; }kPVtSQ  
} ;CmOsA,1  
!N~*EI$  
nem@sB;v#  
public int getNSplitter() L[C*@ uK  
{ gq4 . d  
return nSplitter; dDlG!F_=  
} +,_c/(P  
mk=#\>  
V0NVGRQ  
public void setNSplitter(int nCount) Lt>7hBe"  
{ fNoR\5}!  
nSplitter = nCount; fIyPFqf7w)  
} ~@fR[sg<  
} $Jf9;.  
r/AHJU3&eY  
}ND'0*#  
/* ")M;+<c"l  
**Utility.java ;[Tyt[  
*/ \ X$)vK  
package NetFox; -P#nT 2  
;.s: X  
t)I0lnbs  
public class Utility { \"d?=uFe  
?}sOG?{  
o#e7,O  
public Utility() j'Wp  
{ SE!L :  
rJ(OAKnY  
7a<_BJXx  
} xNgt[fLpS  
n`<U"$*  
//线程睡眠 (,LL[&;:  
public static void sleep(int nSecond) 'F5)ACA%  
{  :]c=pH  
try{ NG9vml  
Thread.sleep(nSecond); d@g2k> >  
} #F4X}  
catch(Exception e) |s|/]aD}o  
{ e2Jp'93o'  
e.printStackTrace (); 8^X]z|2  
} },PBqWe  
} UC|JAZL  
O71BM@2<  
//日志 RgGA$HN/  
public static void log(String sMsg) g1qi\axm  
{ 8]C1K Zs  
System.err.println(sMsg); 7) 0q--B  
} 2U%qCfh6|  
}n95< {  
S=O$JP79  
public static void log(int sMsg) Wz{%"o  
{ !K\itOEP-  
System.err.println(sMsg); 8c).8RLf  
} H[BYE  
} C*G/_`?9  
*Sb2w*c>  
fuyl/bx}  
/* T.@sq  
**TestMethod.java ,?y7 ,nb  
*/ HRHrSf7  
package NetFox; D rTM$)  
c[{UI  
vYzVY\   
public class TestMethod { `M rBav  
gj;@?o0  
if@,vc  
public TestMethod()  /q*KO\L  
{ ///xx/weblogic60b2_win.exe ':sTd^V  
try{ {8:o?LnMW  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b~as64  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;[~^( . f  
SiteFileFetch fileFetch = new SiteFileFetch(bean); xBWx+My  
fileFetch.start(); i+AUQ0Zbf6  
} [q$e6JwAt  
catch(Exception e){e.printStackTrace ();} pqq?*\W&[v  
g)cY\`&W8  
} J(1V!EA  
} ]ymC3LV]  
.K7C-Xn=  
6Ahr_{  
public static void main(String[] args) 7TdQRB  
{ 6 [ _ fD  
new TestMethod(); Ilef+V^qr  
} p`p?li  
} k<O y%+C  
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