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http断点续传简单实现(java)

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/* [;INVUwG^  
**SiteFileFetch.java @2$iFZq~  
*/ U &W}c^#  
package NetFox; F>3fP  
import java.io.*; }xzbg  
import java.net.*; $0E_4#kwB  
+@oo8io  
pK2n'4 C  
public class SiteFileFetch extends Thread { &_c5C  
] yXrD`J!  
] i\a[3  
SiteInfoBean siteInfoBean = null; //文件信息Bean h5#V,$  
long[] nStartPos; //开始位置 @)wNINvD  
long[] nEndPos; //结束位置 1(U\vMb  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n1)m(,{  
long nFileLength; //文件长度 ) /<\|mR  
boolean bFirst = true; //是否第一次取文件 >*mLbp"  
boolean bStop = false; //停止标志 6JL:p{RLi  
File tmpFile; //文件下载的临时信息 3UX})mW  
DataOutputStream output; //输出到文件的输出流 [R[Suf  
M}6? |ir  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #6<9FY#  
public SiteFileFetch(SiteInfoBean bean) throws IOException cS1BB#N0  
{ FmRa]31W  
siteInfoBean = bean; R'r^v  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ^t\AB)(8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z66@@?`  
if(tmpFile.exists ()) 3F0:v,+;  
{ H0B"?81  
bFirst = false; I806I@ix  
read_nPos(); 4 p(KdYc  
} pb5'5X+  
else =#<TE~n2(  
{ D~Y 3\KP  
nStartPos = new long[bean.getNSplitter()]; VXAgp6  
nEndPos = new long[bean.getNSplitter()]; "i1~YE  
} Ls^$E  
COK7 i^  
Ci ? +Sl  
7MT[fA8^  
} b1;80P/:D  
Q04iuhDO:  
[Hww3+~+  
public void run() $u9y H Z  
{ K G~fDb  
//获得文件长度 U:`g12  
//分割文件 { LJRdV  
//实例FileSplitterFetch "+ji`{  
//启动FileSplitterFetch线程 89'XOXl&1  
//等待子线程返回 r=+r5k"`  
try{ 1qb 3.  
if(bFirst) *Gm%Dn  
{ `1KZ14K  
nFileLength = getFileSize(); v:<UbuJw  
if(nFileLength == -1) b&!7(Q[ sT  
{ 4+`<'t]Q  
System.err.println("File Length is not known!"); 7oDr`=q1]r  
} C/+8lA6NV  
else if(nFileLength == -2) ht S5<+Y  
{ QP?Z+P<  
System.err.println("File is not access!"); qf9.S)H1Z  
} ,bCPO` 45  
else S3Tww]q  
{ -C5Qh&~W  
for(int i=0;i<nStartPos.length;i++) q7wd96G:  
{ _~DFZt@T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); VWG#v #o  
} M#d_kDMw  
for(int i=0;i<nEndPos.length-1;i++) x 1$tS#lS  
{ =1%3". "n@  
nEndPos = nStartPos[i+1]; Y2w 9]:J  
} '@Y@H,  
nEndPos[nEndPos.length-1] = nFileLength; 2|#3rF  
} UPPDs"  
} a$FELlMv  
t.>vLzrU  
Y=4,d4uu  
//启动子线程  OXzJ%&h  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (6?pBdZ  
for(int i=0;i<nStartPos.length;i++) "S^;X @#v  
{ ]`y4n=L.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OlFls 8#>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >0i?}  
nStartPos,nEndPos,i); (9$/r/-a  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a)[XJLCQ  
fileSplitterFetch.start(); r 06}@7  
} t4UKG&[a  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l<{]%=Qg  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^gh/$my;  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Lqbu]  
nEndPos = " + nFileLength); 5 8p_b  
// fileSplitterFetch[nPos.length-1].start(); "a6 wd  
VA)3=82n  
+*d,non6v  
//等待子线程结束 sN 7I~  
//int count = 0; F1)Q#ThF\  
//是否结束while循环 ^,b*.6t  
boolean breakWhile = false; ev#d1s|<S  
B.K"1o  
dt) BMF8  
while(!bStop) Lz=nJn  
{ T2} I,{U  
write_nPos(); $ah, $B  
Utility.sleep(500); _$wWKJy9  
breakWhile = true;  #d*mG =  
^QB/{9#  
f3V&i)w(  
for(int i=0;i<nStartPos.length;i++) #2I[F  
{ RV^2[Gdi  
if(!fileSplitterFetch.bDownOver) Q{H88g^=J  
{ _1dG!!L_  
breakWhile = false; jY:(Tv3~  
break; @o44b!i  
} Nt&}T  
} x7l)i!/$  
if(breakWhile) RXt`y62yK  
break; S]9:3~  
W&z.O  
zScV 9,H1  
//count++; A! <R?  
//if(count>4) )(\5Wk9(  
// siteStop(); d<V+;">2  
} l8GziM{lp  
1b;Aru~l  
A]BG*  
System.err.println("文件下载结束!"); v=i[s  
} zEF3B  
catch(Exception e){e.printStackTrace ();} (Y, @-V  
} 2*Z~J M  
QCa$<~c  
]Vl * !,(i  
//获得文件长度 i<bFF03*S  
public long getFileSize() O<iE,PN)  
{ 5p94b*l  
int nFileLength = -1; 6N~~:Gt  
try{ %nF6n:|:  
URL url = new URL(siteInfoBean.getSSiteURL()); g}$]K! F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;r^8In@6  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3r+vpyu  
2p@Rr7  
vj[ .`fY  
int responseCode=httpConnection.getResponseCode(); }v0oFY$u`H  
if(responseCode>=400) He)v:AH  
{ `"zX<  
processErrorCode(responseCode); D>?%p"e  
return -2; //-2 represent access is error +To{Tm-  
} <z%zz c1s  
lb{*,S  
jp=^$rS6[  
String sHeader; %OfaBv&  
lY.FmF}k  
yFl@ z  
for(int i=1;;i++) d@7 ]=P:  
{ 1f~unb\Gg  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E:&=A 4 %  
//Utility.log(in.readLine());  #XQEfa  
sHeader=httpConnection.getHeaderFieldKey(i); k U*\Fa*E  
if(sHeader!=null) 4 FGcCE3  
{ 4}W*,&_  
if(sHeader.equals("Content-Length")) 3 5B0L.R  
{ g>/,},jv[x  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y''`73U"  
break; 'r(}7>~fC  
} $MfHA~^  
} 1 c3gHc7{t  
else Pqo"~&Y|~  
break; *S:^3{.m=  
} "sUL"i  
} dF5EIPl;J  
catch(IOException e){e.printStackTrace ();} >y(;k|-$  
catch(Exception e){e.printStackTrace ();} ?\(E+6tpP  
]6GdB3?UVM  
 zy  
Utility.log(nFileLength); |@sUN:G4k  
1bYc^(z0  
+Z/ *=;  
return nFileLength; ? Z.p.v  
} '.c [7zL  
|k^'}n  
F7Mf>."  
//保存下载信息(文件指针位置) *_!nil3(i  
private void write_nPos() }XX)U_ x  
{ pBL,kqYNA>  
try{ O B_g:T  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Uk` ym  
output.writeInt(nStartPos.length); )c^Rc9e/  
for(int i=0;i<nStartPos.length;i++) l"W9uS;\T  
{ QpBgG~h"  
// output.writeLong(nPos); r.lH@}i%n  
output.writeLong(fileSplitterFetch.nStartPos); Dwj!B;AZ_  
output.writeLong(fileSplitterFetch.nEndPos); K9njD#/  
} $.a<b^.Xi  
output.close(); blpX_N  
} s+#gH@c  
catch(IOException e){e.printStackTrace ();} :"5i/Cx  
catch(Exception e){e.printStackTrace ();} ='`z  
} )^qM%k8  
zq>pK_WG  
=3]}87  
//读取保存的下载信息(文件指针位置) 9E'fM  
private void read_nPos() MCZTeYnx  
{ E2 Q[  
try{ 6}6;%{p"Gu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b|^g51v  
int nCount = input.readInt(); B8F.}M-!  
nStartPos = new long[nCount]; '- oS=OrZ  
nEndPos = new long[nCount]; ~Z9Eb|B  
for(int i=0;i<nStartPos.length;i++) ]P;uQ!  
{ "1FPe63\*O  
nStartPos = input.readLong(); P"Lk(gY  
nEndPos = input.readLong(); ]v(8i3P84  
} 4nK\gXz19  
input.close(); x$Y44v'>  
} UbNA|`H  
catch(IOException e){e.printStackTrace ();} @<=xfs  
catch(Exception e){e.printStackTrace ();} m \o<a|  
} #tg,%*.s  
d[E~}Dq3#  
'3TwrY?-  
private void processErrorCode(int nErrorCode) 4QC"|<9R  
{ AFE6@/'  
System.err.println("Error Code : " + nErrorCode); !~Gx@Ro  
}  J@sH(S  
sU!h^N$  
sL" h  
//停止文件下载 me:~q#k  
public void siteStop() t5t,(^;f  
{ QK%Nt  
bStop = true; GKT2x '(e  
for(int i=0;i<nStartPos.length;i++) !~Vo'ykwx'  
fileSplitterFetch.splitterStop(); 2;Vss<hR4A  
8=QOp[w   
Zk,` Iq  
} ZByxC*Cz  
} Tzr_K  
//负责部分文件的抓取 \|e>(h!l;  
**FileSplitterFetch.java aF*KY<w  
*/ 8Na.H::cZ  
package NetFox; <Qg).n>;z  
Lzmdy0!'  
4<V%7z_.B  
import java.io.*; ?*DM|hzOi  
import java.net.*; < z':_,  
Y-2IAJHS8  
{1?94rz  
public class FileSplitterFetch extends Thread { mj{B_3b5  
Kny0 (  
d*qb^C{'"  
String sURL; //File URL (LiS9|J!  
long nStartPos; //File Snippet Start Position e"}JHXs  
long nEndPos; //File Snippet End Position  +kA>^  
int nThreadID; //Thread's ID  NOY`1i  
boolean bDownOver = false; //Downing is over *vy^=Yea  
boolean bStop = false; //Stop identical MB7UI8  
FileAccessI fileAccessI = null; //File Access interface L`'#}#O l  
?'_Ty`vT  
s;brs}  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \r %y^G  
{ HQp\0NC]  
this.sURL = sURL; UY>[  
this.nStartPos = nStart; @jL](Mq|]  
this.nEndPos = nEnd; CdBpz/  
nThreadID = id; (vX) <Z !  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1G}f83yR  
} 6=cfr; BH2  
vHJOpQmt~  
LNz  
public void run() @%lkRU)  
{ fe!eZiE  
while(nStartPos < nEndPos && !bStop) uzoI*aqk-s  
{ rn$G.SMgz  
2xLEB&  
]I,(^Xq3a(  
try{ =Bg $OX  
URL url = new URL(sURL); Vc[aNpE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BGd# \2  
httpConnection.setRequestProperty("User-Agent","NetFox"); SFu]*II;{  
String sProperty = "bytes="+nStartPos+"-"; sX@}4[)<&  
httpConnection.setRequestProperty("RANGE",sProperty); }SfS\b{|~  
Utility.log(sProperty); o3"Nxq"U  
c,2OICj  
K`=9"v'f+  
InputStream input = httpConnection.getInputStream(); bO i-QD  
//logResponseHead(httpConnection); }/w]+f*  
gt(^9t;  
f+ cN'jH E  
byte[] b = new byte[1024]; (himx8Uml2  
int nRead; 0OXl`V`w  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YpOcLxFL  
{ oF0DprP@  
nStartPos += fileAccessI.write(b,0,nRead); M7[GwA[Z +  
//if(nThreadID == 1) yk0tA  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XS}-@5TI  
} xfF;u9$;  
"MvSF1  
HA J[Y3d<  
Utility.log("Thread " + nThreadID + " is over!"); jY2mn".N  
bDownOver = true; 3'Hz,qP  
//nPos = fileAccessI.write (b,0,nRead); UX2@eyejQ7  
} zfD@/kU  
catch(Exception e){e.printStackTrace ();} \#h{bnx  
} mm9uhlV8  
} qeW.~B!B  
4Q!|fn0Sv  
fikDpR  
//打印回应的头信息 ~<.{z]*O  
public void logResponseHead(HttpURLConnection con) HUAbq }  
{ $bDaZGy  
for(int i=1;;i++)  Y(  
{ uHsLlfTn  
String header=con.getHeaderFieldKey(i); o}&{Y2!x  
if(header!=null) eslvg#Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]K3bDU~  
Utility.log(header+" : "+con.getHeaderField(header)); n0LNAhM  
else A0>r]<y  
break; V|hwT^h  
} $dxA7 `L  
} !{4'=+  
 ZC%;5O`  
x=Aq5*A0  
public void splitterStop() <-mhz`^  
{ >=d 5Scix  
bStop = true; 2FW"uYA;6  
} ]WzeJ"r {3  
\#PZZH%  
diNAT`|?#  
} z9:yt5ar  
P:_bF>r ?  
#sg*GK+|:R  
/* aZ|?i }  
**FileAccess.java E]v]fy"  
*//文件访问(定位,写) !MrQ-B(  
package NetFox; 73 4t  
import java.io.*; >S-JAPuO  
vsyg u  
&qK:LHhj  
public class FileAccessI implements Serializable{ 2~ 4&4  
P^# 4m  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f`KO#Wc  
RandomAccessFile oSavedFile; +~BP~  
long nPos; 6uv~.-T<l  
J>k 6`gw  
ZqdoYU'  
public FileAccessI() throws IOException /\_n5XI1  
{ i6A9|G$H  
this("",0); 98)C 7N'  
} K@JaN/OM  
AAs&P+;  
w[D]\>QHa  
public FileAccessI(String sName,long nPos) throws IOException hkyO_ns  
{ YF-A8gXS  
oSavedFile = new RandomAccessFile(sName,"rw"); SB08-G2  
this.nPos = nPos; /Wcx%P  
oSavedFile.seek(nPos); *sZH3:  
} O@ H.k<zn  
K,JK9)T  
n((A:b  
public synchronized int write(byte[] b,int nStart,int nLen) %$kd`Rl}  
{ #Q)r6V:  
int n = -1; lz ::6}  
try{ >d=pl}-kOQ  
oSavedFile.write(b,nStart,nLen); wPm  
n = nLen; 83I 5n&)  
} !4cY^4>o  
catch(IOException e) rjiHP;-t1  
{ ^H7xFd|>  
e.printStackTrace (); W;cY g.W2  
} <ShA_+Nd  
4xq|  
R|'W#"{@  
return n; ,Pcg+^A  
} m2"e ]I  
<K<#)mcv  
pqb`g@  
} Q K#wsw  
fqY'Uq$=  
OA=~ i/n~  
/* wBwTJCX  
**SiteInfoBean.java !`RMXUV  
*/ s2NBYDi$?  
package NetFox; kE .4 #  
"f_qG2A{  
G"E_4YkJ  
public class SiteInfoBean { 'sH_^{V2  
T}=^D=  
rIJPgF  
private String sSiteURL; //Site's URL ;Su-Y!&%  
private String sFilePath; //Saved File's Path e2N K7  
private String sFileName; //Saved File's Name \.O&-oi  
private int nSplitter; //Count of Splited Downloading File -,b+tC<V)0  
pv sa?z;rP  
;>jEeIlT  
public SiteInfoBean() Q2- lHn^L:  
{//nSplitter的缺省值为5 @-L]mLY  
//default value of nSplitter is 5 oPr`SYB  
this("","","",5); ;*<R~HJt  
} 1S!}su,uH  
{9}CU~R  
5!fYTo|G>  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?YS>_ MN  
{ @WS77d~S  
sSiteURL= sURL; T\bP8D  
sFilePath = sPath; -yc YQ~R  
sFileName = sName; uf#h~;B  
this.nSplitter = nSpiltter; QJ4$) Fr(  
"QNQ00[T`>  
O_a^|ln&  
} (~zu4^9w  
-wiQ d@X  
A| A#|D  
public String getSSiteURL() =FhP$r*  
{ yiC7)=  
return sSiteURL; I ]ZZN6"  
} IJGw<cB]+  
4 O8ct,Y  
4/`;(*]Fv  
public void setSSiteURL(String value) (vZ-0Ep}  
{ .waw=C  
sSiteURL = value; ^wd@mWxx  
} b-VygLN  
+`k30-<P  
=b:XL#VA  
public String getSFilePath() W<pr Y  
{ e7@ m i  
return sFilePath; %5gdLm!p  
} oc( '!c  
D/."0 #q  
H)D|lt5xy  
public void setSFilePath(String value) fF0i^E<  
{ Tt)z[^)%  
sFilePath = value; {V QGfN  
} 1$vGQ  
}OAU5P!rp  
b`#YJpA  
public String getSFileName() `w:kY9  
{ I!Z`'1"  
return sFileName; F*PhV|XU  
} C LaQE{  
?lsK?>uU  
|z=`Ur@)  
public void setSFileName(String value) wg?}c ;  
{ z.cDbkf}  
sFileName = value;  *XhlIQ  
} ,w#lUg p  
cWkg.ri-x  
hD ~/ywS&  
public int getNSplitter() bN. G%1  
{ ;pW8a?  
return nSplitter; ~rBFP)  
} DPzW,aIgv  
y 9]d{:9  
h(/? 81:  
public void setNSplitter(int nCount) f1_;da  
{ M#'7hm6  
nSplitter = nCount; 9<_hb1'  
} A?lL K&*  
} 3$ ! QP N  
]AY 4bm  
; CCg]hX  
/* Zmyq6.1q~  
**Utility.java ! *sXLlS  
*/ @n)? =[p  
package NetFox; lKejWT`;  
uQO5GDuK>  
v8f3B<kj  
public class Utility { "mJo<i}  
lm4A%4-db  
B46:LQ9[  
public Utility() ]vQa~}  
{ S5hc@^|0Z  
FAnz0p+t  
n{4iW_/D  
} %Y ZC dS  
fYP,V0P  
//线程睡眠 NRx 7S 9W  
public static void sleep(int nSecond) $ Lstq_x+  
{ 1!1JT;gG^9  
try{ lu{ *]!  
Thread.sleep(nSecond); V4R s  
} ,9ueHE  
catch(Exception e) %6cr4}Zm}  
{ D=a*Xu2zq  
e.printStackTrace (); ,5c7jZ5H  
} }SSg>.48w  
} Wmd@%K  
0e8  
//日志 66?`7j X  
public static void log(String sMsg) ^N<aHFF  
{ c/K#W$ l  
System.err.println(sMsg); Ja3#W K  
} i`@cVYsL  
{1)bLG|$  
]#M"|iTR  
public static void log(int sMsg) K;"H$0 !9  
{ ;b [>{Q;  
System.err.println(sMsg); p_Xfj2E4c  
} co\?SgE35  
} %t&Lq }e  
qY-aR;  
$CB&>?~  
/* bq7+l4CGTv  
**TestMethod.java A/=cGE  
*/ E4Q`)6]0  
package NetFox; w-WAgAch  
"-S!^h/v  
'~ b  
public class TestMethod { Qf0P"s`  
Z|@-=S(.  
LeN }Q  
public TestMethod() `{YOl\d_  
{ ///xx/weblogic60b2_win.exe \_.'/<aQ  
try{ bP$e1I3`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %GjG.11V,_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7vgRNzZoq  
SiteFileFetch fileFetch = new SiteFileFetch(bean); s8(Z&pQ  
fileFetch.start(); |u`YT;`!"-  
} d >L8S L  
catch(Exception e){e.printStackTrace ();} '(r?($s  
&S.p%Qe"  
N''xdz3Z  
} 0 F8xS8vK+  
WuVsW3@  
u@D5SkT  
public static void main(String[] args) L~+aD2 E {  
{ GAH<  
new TestMethod(); VKXi*F9  
} 7]u_  
} 8u[.s`^  
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