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http断点续传简单实现(java)

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/* CC;! <km  
**SiteFileFetch.java hI pKJ&hm  
*/ ES<{4<Kpx  
package NetFox; W>M~Sk$v  
import java.io.*; hh~n#7w~IR  
import java.net.*; FuX 8v  
dY" }\v6  
~|wos-nM  
public class SiteFileFetch extends Thread { i)Lp7m z  
!:LJzROh  
4yaxl\2  
SiteInfoBean siteInfoBean = null; //文件信息Bean ecOy6@UDY  
long[] nStartPos; //开始位置 d7cg&9+  
long[] nEndPos; //结束位置 ;nmM7TZ;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8hA^`Y  
long nFileLength; //文件长度 Fg/dS6=n`?  
boolean bFirst = true; //是否第一次取文件 wA`"\MWm  
boolean bStop = false; //停止标志 gPzL*6OS A  
File tmpFile; //文件下载的临时信息 NZu)j["  
DataOutputStream output; //输出到文件的输出流 44\>gI<  
7@a 0$coP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `>D9P_Y"jI  
public SiteFileFetch(SiteInfoBean bean) throws IOException 7%OKH<i\2<  
{ aFY_:.o2k`  
siteInfoBean = bean; O3n_N6| q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (#q<\`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); `\<37E\N}  
if(tmpFile.exists ()) ,jy*1Hjd  
{ }a&mY^  
bFirst = false; Pw@olG'Ah  
read_nPos(); 5&CDHc7Oj  
} rZ_>`}O2  
else i.iio-  
{ kllQca|$4  
nStartPos = new long[bean.getNSplitter()]; oKFT? "[X  
nEndPos = new long[bean.getNSplitter()]; JO@ Bf  
} kqvow3u  
W[NEe,.>  
,J mbqOV?!  
`-B+JQmen  
} '?o9VrO  
o@lWBfB*%e  
,]Zp+>{  
public void run() LF*Q!  
{ <Wl(9$  
//获得文件长度 ,/&Zw01dGN  
//分割文件 }tST)=M`  
//实例FileSplitterFetch %up}p/?  
//启动FileSplitterFetch线程 ;52'}%5  
//等待子线程返回 V'Qn sI  
try{ km:nE: |  
if(bFirst) %@ mGK8  
{ i(2y:U3[@  
nFileLength = getFileSize(); Z\>, ),O  
if(nFileLength == -1) {bF1\S]2  
{ 0)uYizJce  
System.err.println("File Length is not known!"); Y9r3XhVI  
} }bB` (B,m  
else if(nFileLength == -2) h3u1K>R)  
{ ]_*S~'x  
System.err.println("File is not access!"); ED![^=  
} ARh6V&Hi-  
else w#G2-?aj  
{ KA]*ox6j;  
for(int i=0;i<nStartPos.length;i++) yno('1B@  
{ =G-N` 39  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6k])KlJ2;  
} 4ax|Vb)D  
for(int i=0;i<nEndPos.length-1;i++)  W^g[L:s  
{ w,.qCpT$_  
nEndPos = nStartPos[i+1]; !UV5zmS  
} N:+ taz-  
nEndPos[nEndPos.length-1] = nFileLength; fW0$s`  
} /k:$l9C[  
} 83 ]PA<R  
00vBpsZj2;  
b_$ 1f >  
//启动子线程 xc'vS>&  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1 H4fJ3-  
for(int i=0;i<nStartPos.length;i++) y@vj;3:  
{ Q]JX`HgPaU  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &hZwZgV +3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?Z %:  
nStartPos,nEndPos,i); p5 ]_}I`+2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BQgoVnQo_c  
fileSplitterFetch.start(); {_ V0  
} "/x_>ui1F  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), whc[@Tyx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~o15#Pfn/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b#Kq[}  
nEndPos = " + nFileLength); (wt+`_6  
// fileSplitterFetch[nPos.length-1].start(); k{Lv37H  
/Ic[N&  
OHp5z? z  
//等待子线程结束 p6 xPheD  
//int count = 0; v"1Po_`  
//是否结束while循环 =fG:A(v%}  
boolean breakWhile = false; zQuM !.  
2:v<qX  
@Jv# fr  
while(!bStop) z%"Ai)W/{  
{ \SYvD y]  
write_nPos(); |'hLa  
Utility.sleep(500); "G?9b  
breakWhile = true; SN]LeXesS  
,jh~;, w2  
-l*A  
for(int i=0;i<nStartPos.length;i++) \aSz2lxEHn  
{ ZCiY,;c  
if(!fileSplitterFetch.bDownOver) o42`z>~  
{ Pern*x9$  
breakWhile = false; {7#03k  
break; x*8O*!ZZ  
} h W.2p+  
} C|e+0aW  
if(breakWhile) $-G`&oT  
break; Lar r}o=  
Lx+`<<_dJ  
12gw#J/)9h  
//count++; fD6GQ*  
//if(count>4) emWGIo  
// siteStop(); .LE+/n  
} .H;B=nd*  
c4]u&tvjJ  
;L6Xs_L~  
System.err.println("文件下载结束!"); L$JI43HZ  
} wJIB$3OT  
catch(Exception e){e.printStackTrace ();} Ph)| j&]  
} oX|?:MS:  
QrS$P09=\  
!t-K<'  
//获得文件长度 9O >z4o  
public long getFileSize() 9)ea.Gu  
{ ~mA7pOHj  
int nFileLength = -1; L+R >%d s  
try{ vfbe$4mH  
URL url = new URL(siteInfoBean.getSSiteURL()); 7*'@qjTos  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rWr/p^~  
httpConnection.setRequestProperty("User-Agent","NetFox"); yh!B!v'  
8eX8IR!K9  
05)|"EX)  
int responseCode=httpConnection.getResponseCode(); l{EU_|q  
if(responseCode>=400) Yo'K pdn  
{ (T;9us0  
processErrorCode(responseCode); T&/_e   
return -2; //-2 represent access is error nLd~2qBuv  
} &z ksRX  
NV~vuC  
Zz")`hUG  
String sHeader; JD&U}dJ  
#: hVF/  
)0|):g   
for(int i=1;;i++) /co%:}ln  
{ j`9Nwa  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3H'*?|Y(#  
//Utility.log(in.readLine()); FfXZ|o$;  
sHeader=httpConnection.getHeaderFieldKey(i); K -E`y  
if(sHeader!=null) DB8s  
{ 1f;or_f#k?  
if(sHeader.equals("Content-Length")) 41 'EA \V  
{ ,9vJtP+T+!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kH2oK:lN  
break; m<FK;   
} C1ZyB"{  
} o*;2mFP  
else )Pa*+ew7  
break; +2yF|/WW#  
} u:5IjOb2^  
} $3:X+X  
catch(IOException e){e.printStackTrace ();} )[ b#g(Y(  
catch(Exception e){e.printStackTrace ();} @LC~*_y   
UT;4U;a,m  
}} #be  
Utility.log(nFileLength); dJE`9$jN  
X 7&U3v  
@ RX`>r{_  
return nFileLength; |D(&w+(  
} {Y "8~  
aH^{Vv$]M@  
tQf!|]#J  
//保存下载信息(文件指针位置) ^Fvr f`A'  
private void write_nPos() T^NJ4L4#  
{ o'^phlX  
try{ Z"N(=B  
output = new DataOutputStream(new FileOutputStream(tmpFile)); x _|>n<Z  
output.writeInt(nStartPos.length); qOgtGN}k  
for(int i=0;i<nStartPos.length;i++) bQV("~#  
{ oVEAlBm^v  
// output.writeLong(nPos); < 4$YO-:E  
output.writeLong(fileSplitterFetch.nStartPos); X#7}c5^Y  
output.writeLong(fileSplitterFetch.nEndPos); v,*Q]r0m  
} D+hB[*7Fs  
output.close(); #{~7G%GPY5  
} |Cq8%  
catch(IOException e){e.printStackTrace ();} DUo0w f#D^  
catch(Exception e){e.printStackTrace ();} N*':U^/t4J  
} wO!% q[  
3B -NY Ja  
xfes_v""  
//读取保存的下载信息(文件指针位置) ?"u'#f_  
private void read_nPos() )O -cw7 >  
{ 26}u4W$  
try{ FdM<;}6T  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g~|y$T  
int nCount = input.readInt(); R9q0,yQW  
nStartPos = new long[nCount]; 59~FpjJ  
nEndPos = new long[nCount]; r hZQQOQ  
for(int i=0;i<nStartPos.length;i++) c-`37. J  
{ r8F{A6iN  
nStartPos = input.readLong(); Mb~~A5  
nEndPos = input.readLong(); b_ZNI0Hp@  
} pd7O`.3  
input.close(); t#{x?cF  
} e@yx}:]h  
catch(IOException e){e.printStackTrace ();} )5'rw<:="  
catch(Exception e){e.printStackTrace ();} H8sK}1.  
} ,b4~!V  
3Cd<p[%3#,  
[xWEf#', !  
private void processErrorCode(int nErrorCode) Tfr`?:yF  
{ \d ui`F"Cc  
System.err.println("Error Code : " + nErrorCode); {sl~2#,}b1  
} avV mY|I  
YV4 : 8At1  
EZ*t$3.T  
//停止文件下载 _Ws#UL+Nq  
public void siteStop() 4*H(sq  
{ tr5'dX4]  
bStop = true; +*: }p  
for(int i=0;i<nStartPos.length;i++) S;>4i!Mb ^  
fileSplitterFetch.splitterStop(); C)U #T)  
),M U+*`  
9n-T5WP  
} e"lD`*U8R  
} (;C$gnr.C  
//负责部分文件的抓取 2c"/QT  
**FileSplitterFetch.java '1Y<RD>x  
*/ T<XfZZ)l<`  
package NetFox; 8F\~Wz7K  
(y 3~[  
ZRX^^yN  
import java.io.*; ^uM_b  
import java.net.*; BB0g}6M  
k"5`:qL  
\ hrBq^I  
public class FileSplitterFetch extends Thread { gO9'q='5l  
u/;_?zI  
2 ae w6~  
String sURL; //File URL `!<x"xKu  
long nStartPos; //File Snippet Start Position \)p4okpR  
long nEndPos; //File Snippet End Position ^4RO  
int nThreadID; //Thread's ID ~d&'Lp[3  
boolean bDownOver = false; //Downing is over Tm%WWbc  
boolean bStop = false; //Stop identical aD?# ,  
FileAccessI fileAccessI = null; //File Access interface Z(l9>A7!  
%Fs*#S  
5Ws5X_?d  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AL(n *,  
{ i[o&z$JO  
this.sURL = sURL; -<]\l3E&J  
this.nStartPos = nStart; Av@& hD\  
this.nEndPos = nEnd; gHp'3SnS  
nThreadID = id; >c}:   
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0&.LBv8  
} zoR,RBU6  
CQj/e+eE4  
x`Vy<h 33  
public void run() 4u@yJ?U  
{ <zfO1~^  
while(nStartPos < nEndPos && !bStop) =VCi8jDkP  
{ /]pX8 d  
_RN/7\  
W]} #\\$z  
try{ u):X>??  
URL url = new URL(sURL); jG =(w4+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A J<iM)l|  
httpConnection.setRequestProperty("User-Agent","NetFox"); X77A; US  
String sProperty = "bytes="+nStartPos+"-"; @gs26jX~2}  
httpConnection.setRequestProperty("RANGE",sProperty); 37J\i ]  
Utility.log(sProperty); <GSQ2bX[  
ww-XMz h  
|*lH9lWJ  
InputStream input = httpConnection.getInputStream(); A$%@fO.b  
//logResponseHead(httpConnection); Q~x*bMb.  
j@%K*Gb`  
>|v=Ba6R0  
byte[] b = new byte[1024]; p Z0=  
int nRead; eL>K2Jxq  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z'voCWCd  
{ bMSD/L  
nStartPos += fileAccessI.write(b,0,nRead); 8W(<q|t  
//if(nThreadID == 1) Ti0 (VdY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ac2}3 $u  
} N;e;4,_ n  
OJnPP>  
-OHvK0~  
Utility.log("Thread " + nThreadID + " is over!"); pI'8>_o  
bDownOver = true; _K 4eD.  
//nPos = fileAccessI.write (b,0,nRead); $ijx#a&O  
} 8yY"x ['  
catch(Exception e){e.printStackTrace ();} 71K\.[ =-  
} Na~g*)uT$  
} +J\L4ri k  
p*A^0DN'Fn  
.q AQP L  
//打印回应的头信息 ~,(0h:8  
public void logResponseHead(HttpURLConnection con) 113Z@F  
{ SIKk|I)  
for(int i=1;;i++) d)`nxnbMeM  
{ \9dz&H  
String header=con.getHeaderFieldKey(i); trID#DT~  
if(header!=null) n,C D4Nv  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l=Lmr  
Utility.log(header+" : "+con.getHeaderField(header)); ^G ]KE8  
else 4v rm&k  
break; :6\-9m8JM  
} uYG #c(lc  
} HV]~=Bw2I  
+ TPbIRA  
>WGX|"!"  
public void splitterStop() m]+X }|  
{  9'L1KQ  
bStop = true; ucIVVT(u  
} T{5M1r  
|U;w!0  
$bF`PGR_  
} $ioaunQKP  
TMnT#ypf<5  
umq$4}T '$  
/* z{ Zimr  
**FileAccess.java Qs#9X=6e@  
*//文件访问(定位,写) ?M*C*/R  
package NetFox; Hl4vLx@  
import java.io.*; &F@tmM~  
'=@-aVp  
"B_5Y&pM`  
public class FileAccessI implements Serializable{ Zq2H9^![y~  
g7E`;&f  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ONg<  
RandomAccessFile oSavedFile; ~m,mvRS  
long nPos; \? 5[RR  
JCCx 5  
:O>Nd\UtO  
public FileAccessI() throws IOException I(iGs I  
{ i]h R7g<  
this("",0); =CD:.FG.  
} A;/Xt  
fzPgX  
K284R=j -&  
public FileAccessI(String sName,long nPos) throws IOException }RC. Q`b  
{ 4nVO.Ud0$X  
oSavedFile = new RandomAccessFile(sName,"rw"); (o6A?37i  
this.nPos = nPos; K4K3< Pg  
oSavedFile.seek(nPos); -7C=- \]  
} (AyRs7Dkn  
hs -}:^S`  
#U6/@l)  
public synchronized int write(byte[] b,int nStart,int nLen) /_ hfjCE  
{ g:@Cg.q8  
int n = -1; |zr)hC  
try{ A ydy=sj  
oSavedFile.write(b,nStart,nLen); uMq\];7I  
n = nLen; 6 ^6uK  
} {kY`X[fvZ  
catch(IOException e) z~A(IQO  
{ 1*eWvYo1  
e.printStackTrace (); A-@-?AR  
} >E 2WZHzd2  
Hsux>+Q  
%Pt[3>  
return n; unbcz{&Hb[  
} K7d1(.  
HeAc(_=C  
`siy!R  
} "~ i#9L/H  
:#"OCXr  
U 8 .0L  
/* $D2Ain1  
**SiteInfoBean.java * (XgUJ q+  
*/ c+\Gd}IJq  
package NetFox; QKL]O*  
QtO[g  
= -a?oH-  
public class SiteInfoBean { y+~Aw"J}  
.,iw2:  
l*V72!Mv  
private String sSiteURL; //Site's URL (t"YoWA#m  
private String sFilePath; //Saved File's Path PHB\)/  
private String sFileName; //Saved File's Name *< SU_dAh  
private int nSplitter; //Count of Splited Downloading File N]<~NG:6b  
F0o18k_"  
oeU+?-y/b  
public SiteInfoBean() `b,g2XA  
{//nSplitter的缺省值为5 G@l|u  
//default value of nSplitter is 5 vr]dRStr  
this("","","",5); 5"Xo R)  
} 6b1 Uj<  
mhHm#  
::Ve,-0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n$\6}\k  
{  =}1~~  
sSiteURL= sURL; K`AW?p^$Y  
sFilePath = sPath; {3 yws 4  
sFileName = sName; lf7H8k,-  
this.nSplitter = nSpiltter; 7C 6BZ$(  
}e;p8)]Wl  
nh_xbo5L[  
} 9i xnf=$Jp  
G#=b6DB  
S3[oA&  
public String getSSiteURL() L:];[xa%  
{ hF?\K^tF  
return sSiteURL; e1Z;\U$&.  
} # xE>]U  
s9)8{z  
J1wGK|F~  
public void setSSiteURL(String value) %>QSeX  
{ e[Ul"pMvS`  
sSiteURL = value; l=.InSuLT  
} DyV[+P  
(j\UoKLRt  
bgx5{!A  
public String getSFilePath() _M[[o5{  
{ (>/Dw|,m  
return sFilePath; r;s3(@[,@  
} )Z`viT  
.~/;v~bL  
}N=zn7W  
public void setSFilePath(String value) I5AjEp  
{ jq]\oY8y  
sFilePath = value; ]{l O  
} 4?6'~G$k  
\}_7^)S;  
L``mF(R^  
public String getSFileName() =dJEcC_J  
{ :y)&kJpleP  
return sFileName; tLGwF3e$A  
} 7 5cr!+  
vmQ DcCw  
&qj&WfrB,  
public void setSFileName(String value) E!]rh,mYK  
{ :j!_XMyT:  
sFileName = value; wz2)seZY  
} UM;bVf?  
B=qRZA!DQ?  
AF nl t  
public int getNSplitter() [}B{e=`!  
{ l=G#gKE  
return nSplitter; <Ucfd G&Lp  
} (inwKRH  
v6(l#,  
gl4 f9Ff  
public void setNSplitter(int nCount) )e$-B]>7z  
{ BB}iBf I'  
nSplitter = nCount; s#CEhb  
} !haXO  
} 5|H(N}S_  
t@mw f3,  
5+PBS)pJ]%  
/* RAJ |#I1  
**Utility.java Kwmo)|7uPU  
*/ ;bu;t#  
package NetFox; '48|f`8$  
eh# (}v  
-cC(d$y  
public class Utility { olW`.3f  
_p^ "!  
w\[*_wQp  
public Utility() sJ*U Fm{  
{ 0hr)tYW,G  
LGue=Hkp  
g{.@|;d <p  
} <\Dl#DH  
)=y6s^}  
//线程睡眠 |Szr=[  
public static void sleep(int nSecond) ~ .=HN}E  
{ rY+1s^F  
try{ |0Ug~jKU  
Thread.sleep(nSecond); 7o%|R2mL}  
} {@`Uf;hPAX  
catch(Exception e) =*G'.D /*  
{ <{~UKi  
e.printStackTrace (); ;&:Et  
} A ba%Gh  
} \{^yB4F_Z  
?DTP-#5Ba  
//日志 h1d 0{  
public static void log(String sMsg) B$eF@v"  
{ S~`AnX3!  
System.err.println(sMsg); Or~6t}f  
} : l[Q  
nqW:P$  
im%3*bv-  
public static void log(int sMsg) 2n,73$ s  
{ 833t0Ml1A/  
System.err.println(sMsg); "+C\f)  
} y^fU_L?p  
} sX?7`n1U  
UjK&`a ;V  
SQ.Wj?W)  
/* Dy'l]vN$  
**TestMethod.java qt;Tfuo  
*/ V'4}9J  
package NetFox; 0X6o  
qOanu  
pNsLoNZ3w  
public class TestMethod { (M?Q9\X  
_ q1|\E%`h  
+F6_P  
public TestMethod() =1?yS3  
{ ///xx/weblogic60b2_win.exe '.v^seU  
try{ *g}&&$b0  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XsMphZnK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lu5.$b  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1F8EL)9  
fileFetch.start(); -w0>4JDs  
} y`dzo`f  
catch(Exception e){e.printStackTrace ();} (NlEb'~+  
YCdxU1V  
Z*B(L@H  
} (KU@hp-\  
0u9h2/ma  
BGjTa.&  
public static void main(String[] args) |ZzBCL8q  
{ nA j2k  
new TestMethod(); tS@/Bq('B  
} Bbp9Q,4  
} bS"M*  
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