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http断点续传简单实现(java)

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/* ] W_T(C*  
**SiteFileFetch.java xj<SnrrC]u  
*/ Zj;!7ZuT1  
package NetFox; p\K5B,  
import java.io.*; >smaR^m  
import java.net.*; I1,?qr"Zr  
{ex]_V>  
8ZDq KQ1;  
public class SiteFileFetch extends Thread { yS""*8/  
q8J/tw?%v  
b+>godTi_  
SiteInfoBean siteInfoBean = null; //文件信息Bean &AVi4zV  
long[] nStartPos; //开始位置 qz&)|~,\C  
long[] nEndPos; //结束位置 0% /M& N  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 $B2@mC([S  
long nFileLength; //文件长度 RZZB?vx  
boolean bFirst = true; //是否第一次取文件 P}jr 8Z  
boolean bStop = false; //停止标志 |Th{*IJ <,  
File tmpFile; //文件下载的临时信息 K2QD&!4/T2  
DataOutputStream output; //输出到文件的输出流 By9/tB  
`*a,8M%  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) DH%X+r  
public SiteFileFetch(SiteInfoBean bean) throws IOException J98K:SAR  
{ ?0x;L/d])  
siteInfoBean = bean; 21qhlkdc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 92i# It}-/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); c LJCLKJ  
if(tmpFile.exists ()) 'zaB5d~l  
{ R)=<q]Ms  
bFirst = false; ?:E;C<Ar  
read_nPos(); vuf|2!kh/  
} D<`X B*  
else yT4|eHl  
{ VWi-)  
nStartPos = new long[bean.getNSplitter()]; :vjbuqN]  
nEndPos = new long[bean.getNSplitter()]; {~SR>I3sv  
} y[cAU:P?  
~EBZlTN  
*K;~V  
uD"Voh|]=  
} =ZQIpc  
!v-(O"a  
#?9o A4Q  
public void run() iq#Z\Y(  
{ T1E=<q4  
//获得文件长度 [o~w>,a  
//分割文件 ,<BTv;4p  
//实例FileSplitterFetch ?6Gq &  
//启动FileSplitterFetch线程 8c9_=8vw  
//等待子线程返回 &Ru6Yt0W  
try{ ~BC5no  
if(bFirst) c1`o3gb  
{ TsQMwV_h  
nFileLength = getFileSize(); aF:I]]TfK~  
if(nFileLength == -1) 1\Mcs X4  
{ p82qFzq#  
System.err.println("File Length is not known!"); i=ba=-"Mt  
} j{vzCRa>8  
else if(nFileLength == -2) MI/1uw  
{ D"MNlm  
System.err.println("File is not access!"); VioVtP0  
} mXr)lA  
else &zZSWNW  
{ .f}I$ "2  
for(int i=0;i<nStartPos.length;i++) 'BC-'Ot  
{ bke 1 F '  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); iG ;6e~p  
} [# _ceg1G  
for(int i=0;i<nEndPos.length-1;i++) 2eNm2;  
{ (w.B_9#  
nEndPos = nStartPos[i+1]; Pw")|85  
} g%Z;rDfi  
nEndPos[nEndPos.length-1] = nFileLength; <ANKoPNie  
} #&2mu  
} z|9 ^T@)  
T<OLfuV  
ukw'$Yt2  
//启动子线程 dL"v*3Fy  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h3:k$`_  
for(int i=0;i<nStartPos.length;i++) D526X0  
{ "x{S3v4Rb5  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /4|qfF3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Uz0mSfBp  
nStartPos,nEndPos,i); G -;Yua2\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]?kf;A@  
fileSplitterFetch.start(); a}wB7B;,g  
} 6ugBbP +^  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K46\Rm_:B;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g$< @!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R}0c O^V  
nEndPos = " + nFileLength); pY2nv/  
// fileSplitterFetch[nPos.length-1].start();  6} 9A0  
)b =$!  
W?$ ImW  
//等待子线程结束 f.,-KIiF  
//int count = 0; 9+L! A  
//是否结束while循环 ?.T=(-  
boolean breakWhile = false; ?D.] c;PR  
3}H94H)]a  
(Yx rZ_F'b  
while(!bStop) vs.q<i-u  
{ OvFZ&S[  
write_nPos(); pd|c7D!6U,  
Utility.sleep(500); X 6>Pq  
breakWhile = true; '\9A78NV{;  
$rdA0%;  
)wKuumet  
for(int i=0;i<nStartPos.length;i++) TPkm~>zD.  
{ xT@\FwPr  
if(!fileSplitterFetch.bDownOver) nI 6`/  
{ ^,?]]=mE  
breakWhile = false; XpM#0hm  
break; `+<5QtD  
} pdE=9l'  
} 7_JK2  
if(breakWhile) )q#b^( v  
break; "xh]>_;&'  
W nVX)o  
2LgRgY{Bl  
//count++; ~oOOCB  
//if(count>4)  yXDf;`J  
// siteStop(); c=ZX7U  
} E;h#3 B9  
s|q B;  
N&=,)d~M  
System.err.println("文件下载结束!"); -8-Aqh8|  
} ^7(zoUn:  
catch(Exception e){e.printStackTrace ();} 0.?|%;^ib  
} FO*Py)/rX  
D[U5SS!)  
/P,J);Y  
//获得文件长度 ed& ,  
public long getFileSize() IH{g-#U  
{ dLv\H&  
int nFileLength = -1; = uOFaZ4  
try{ 0`_Gj{:L  
URL url = new URL(siteInfoBean.getSSiteURL()); 4).q+{#k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #MI}KmH  
httpConnection.setRequestProperty("User-Agent","NetFox"); o\2#o5#  
];IUiS1  
s7=]!7QGS!  
int responseCode=httpConnection.getResponseCode(); -FJ 5N}R  
if(responseCode>=400) yaeX-'(Fv[  
{ k{9s>l~'  
processErrorCode(responseCode); 5HmX-+XpK  
return -2; //-2 represent access is error y*P[* /g  
} c/pT2/y  
KaOS!e'  
HmQuRW  
String sHeader; w2Pkw'a{  
-[ F<u  
Vk[m$  
for(int i=1;;i++) 3EAu#c@q"  
{ Q~uj:A]n<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G:f]z;Xdp  
//Utility.log(in.readLine()); o-/Xa[yC  
sHeader=httpConnection.getHeaderFieldKey(i); ]{dg"J  
if(sHeader!=null) "Sl";.   
{ h4ZrD:D0\  
if(sHeader.equals("Content-Length")) BjJ+~R  
{ m\j'7mZ1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6N6d[t"  
break; t + Fm?  
} (0^u  
} J5IQ  
else 2E;*kKw[  
break; eja_+`cJ  
} z$;z&X$j  
} DN!:Rm uc  
catch(IOException e){e.printStackTrace ();} oc>,5 x  
catch(Exception e){e.printStackTrace ();} M,:GMO:?a  
\Z<' u;  
J,k9?nkY /  
Utility.log(nFileLength); 5^[V%4y>  
WG< D+P  
AOhsat;O`  
return nFileLength; p.&FK'&[0  
} _v<EFal  
+K]kGF  
-cEjB%Neo  
//保存下载信息(文件指针位置) )mJl-u[0+  
private void write_nPos() 4mUQVzV  
{ <T<?7SE+  
try{ eZT923tD  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +ImPNwrY  
output.writeInt(nStartPos.length); u9QvcD^'z  
for(int i=0;i<nStartPos.length;i++) .\qZkk}2l  
{ <[kdF")  
// output.writeLong(nPos); =((#kDrN  
output.writeLong(fileSplitterFetch.nStartPos); ABB4(_3E  
output.writeLong(fileSplitterFetch.nEndPos); r `VKb  
} z1_\P) M  
output.close(); BY72fy#e  
} $ ^m_M.1  
catch(IOException e){e.printStackTrace ();} JT,8/o  
catch(Exception e){e.printStackTrace ();} KE6[u*\  
} H/Y ZwDx,i  
(+(YO\ng6  
,J~kwJ$L  
//读取保存的下载信息(文件指针位置) Tw);`&Ulo  
private void read_nPos() PO ]z'LD  
{ M+9G^o)u  
try{ o%5^dX&[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2t*@P"e!  
int nCount = input.readInt(); do C8!  
nStartPos = new long[nCount]; >kd&>)9v  
nEndPos = new long[nCount]; R"VmN2  
for(int i=0;i<nStartPos.length;i++) H5{d;L1[  
{ SX$v&L<  
nStartPos = input.readLong(); +QqYf1@F  
nEndPos = input.readLong(); p.n+m[  
} A9!%H6  
input.close(); 7;+:J;xf66  
} a3sXl+$D@  
catch(IOException e){e.printStackTrace ();} a>G|t5w  
catch(Exception e){e.printStackTrace ();} 6m|j " m  
} Ft#d & I  
[0w @0?[  
`c ^2  
private void processErrorCode(int nErrorCode) c4k3|=f  
{ b<~\IPY  
System.err.println("Error Code : " + nErrorCode);  =6Ihk  
} b7p&EK"Hm  
t[Xx LG*  
]]J2#mN:n  
//停止文件下载 U8PSJ0ny  
public void siteStop() EQET:a:g  
{ JF IUD{>fp  
bStop = true; XL1v&'HLV  
for(int i=0;i<nStartPos.length;i++) swntz  
fileSplitterFetch.splitterStop(); 5\A[ra  
_t_X`  
mvyqCOp 0  
} VZ 5EV'D8!  
} j ~:Dr   
//负责部分文件的抓取 CfNHv-jDL  
**FileSplitterFetch.java rfpeX   
*/ Gcna:w>6d  
package NetFox; qe8dpI;  
k,LeBCqGcb  
1D sgU6"  
import java.io.*; 7loIX Qw  
import java.net.*; !'Q/9%g  
s+8 v7ZJ  
q["CT&0  
public class FileSplitterFetch extends Thread { $*tq$DZ4&  
%qfql  
mx y>  
String sURL; //File URL G'{$$+U^K  
long nStartPos; //File Snippet Start Position mp:%k\cF|  
long nEndPos; //File Snippet End Position A]id*RtY  
int nThreadID; //Thread's ID *tC]Z&5  
boolean bDownOver = false; //Downing is over ]L@VpHEj  
boolean bStop = false; //Stop identical -^`]tF`M  
FileAccessI fileAccessI = null; //File Access interface ,|,DXw  
uW3`gwwlU  
V\^3I7F  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WLma)L`L  
{ 9 ,=7Uh#7  
this.sURL = sURL; ( 6|S42  
this.nStartPos = nStart; XbsEO>_Z'A  
this.nEndPos = nEnd; -K9bC3H  
nThreadID = id; P,^`|\#7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E"ijNs  
} 7{e0^V,\k  
2>Bx/QF@<  
K4b# y~@  
public void run() %"Q{|}  
{ y w)q3zC  
while(nStartPos < nEndPos && !bStop) F:"<4hiA"  
{ a;jXMR  
2It$ bz  
_h", ,"p#o  
try{ wg\*FfQn  
URL url = new URL(sURL); yJkERiJV  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |r[yMI|VR  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 UU5\ jV6  
String sProperty = "bytes="+nStartPos+"-"; f0]8/)  
httpConnection.setRequestProperty("RANGE",sProperty); _C$JO   
Utility.log(sProperty); sS/#)/B  
@.T(\Dq^  
`OO=^.-u  
InputStream input = httpConnection.getInputStream(); Bt[OGa(q  
//logResponseHead(httpConnection); &(UVS0=Dp,  
P~$FgAV  
{h5 S=b  
byte[] b = new byte[1024]; u4*7 n-(  
int nRead; l3dGe'  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bU9B2'%E  
{ ;gfY_MXnF  
nStartPos += fileAccessI.write(b,0,nRead); /^v?Q9=Y  
//if(nThreadID == 1) #-?pY"N,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o_>id^$>B  
} a<9cj@h  
WD c2Qt  
5|&8MGW-$  
Utility.log("Thread " + nThreadID + " is over!"); b37P[Q3  
bDownOver = true; P[6@1  
//nPos = fileAccessI.write (b,0,nRead); 6UOV,`:m+  
} *$mDu,'8  
catch(Exception e){e.printStackTrace ();} *)+1BYMo  
} lX$6U| !  
} 3#o!K  
s\A"B#9r  
F[uy'~;@  
//打印回应的头信息 |y=;#A  
public void logResponseHead(HttpURLConnection con) W!|A3V35\:  
{ pcwkO  
for(int i=1;;i++) R L&z\S  
{ -7\Rl3c  
String header=con.getHeaderFieldKey(i); SEsc"l8  
if(header!=null) ckFnQhW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "X4L+]"$g  
Utility.log(header+" : "+con.getHeaderField(header)); ~RGZY/4  
else wmbjL=f Ia  
break; yDh(4w-~gk  
} e]R`B}vO  
} \-3\lZ3qj  
V9 qZa  
0T-y]&uo  
public void splitterStop() mGR}hsQpn  
{ }`M53>C,gQ  
bStop = true; kNqSBzg  
} 3NRxf8  
mNS7/I\  
o;bK 7D  
} 3~ITvH,`s  
JQ|qg\[  
%H OMX{~}#  
/* k{_ Op/k}V  
**FileAccess.java .R5[bXxe7  
*//文件访问(定位,写) dE R#)bGj  
package NetFox; z<2!|  
import java.io.*; t}r`~AEa!  
.XD7};g  
pUtd_8  
public class FileAccessI implements Serializable{ *PQu9>1w  
v,z s dr"d  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0IU>KGJ-0s  
RandomAccessFile oSavedFile; PAG.],"D  
long nPos; 0 ?kaXD  
wc z|Zy  
pm$ZKM  
public FileAccessI() throws IOException |tL57Wu93  
{ tj:3R$a  
this("",0); ANB@cK_  
} \\;i  
<s/n8#i=H  
7d&_5Tj:  
public FileAccessI(String sName,long nPos) throws IOException rUZRYF4C  
{ <WXO].^  
oSavedFile = new RandomAccessFile(sName,"rw"); U^jxKBq^  
this.nPos = nPos; Cw`8[)=}o  
oSavedFile.seek(nPos); )X*?M?~\  
} p0Cp\.  
`CCuwe<v  
WmU5YZ(mAq  
public synchronized int write(byte[] b,int nStart,int nLen) WXz'H),R  
{ ;M,u,KH)/  
int n = -1; C? pi8Xg  
try{ VA4>!t)  
oSavedFile.write(b,nStart,nLen); J[E_n;d1  
n = nLen; {z)&=v@  
} u{Jv6K,  
catch(IOException e) /7WN,a  
{ H:9Z.|{Gv  
e.printStackTrace (); gp07I{0~m  
} :|hFpLt  
+B^(,qKMN  
]L0GIVIE  
return n; @oC# k<  
} }6/L5j:+  
?v-Y1j  
jG($:>3a@  
} D(3\m)  
jDI)iW`P  
8#%Sq=/+M  
/* Nxk3uF^  
**SiteInfoBean.java zJ;K4)"j  
*/ HQi57QB  
package NetFox; >7@kwj-f)  
$Pa7B]A,Ae  
a*4"j2j v  
public class SiteInfoBean { w)x`zVwO  
3L2@C%  
.Q'/e>0  
private String sSiteURL; //Site's URL Wxjv=#3  
private String sFilePath; //Saved File's Path en\shc{R]`  
private String sFileName; //Saved File's Name z;Pr] *F  
private int nSplitter; //Count of Splited Downloading File ]RYk Y7>`  
nya-Io.  
X4<!E#  
public SiteInfoBean() U?/UW;k[  
{//nSplitter的缺省值为5 +rEqE/QF  
//default value of nSplitter is 5 -[-LR }u  
this("","","",5); |Ad1/>8i  
} piIr .]  
3Cq/ o'  
Izrf42 >k  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "=~P&Mi_  
{ Fy4jujP<  
sSiteURL= sURL; -fF1vJ7L  
sFilePath = sPath; [~&C6pR  
sFileName = sName; npcB+6  
this.nSplitter = nSpiltter; xEK+NKTeV  
 & t b  
tCnx:1  
} 99XbpP55  
a }6Fj&hj  
V>#iR>w_4,  
public String getSSiteURL() NwQexYm1_  
{ z-(#Mlq:!  
return sSiteURL; .H1 kl)~V  
} wg6![Uh  
Lo, z7"8  
hK=\O)  
public void setSSiteURL(String value)  ESOuDD2<  
{ q|PB[*T  
sSiteURL = value; ]:* 8 Mb#  
} n^QOGT.s6`  
k;V4%O  
@\gTi;u/x  
public String getSFilePath() /EY ^ui  
{ XOl]s?6H$  
return sFilePath; ; n2|pC^  
} z1\G,mJK  
Mwdh]I,#  
.K![<e Z  
public void setSFilePath(String value) /'|'3J]HP  
{ m35Blg34  
sFilePath = value; 5ug?'TOj'  
} Q(lj &!?1k  
|_l\.  
>V~q`htth  
public String getSFileName() } g  WSV  
{ U\S%Jq*  
return sFileName; uM0!,~&9|  
} \jn[kQ+pJ  
<j1l&H|ux,  
a,Gd\.D  
public void setSFileName(String value) \Cx) ~bq<  
{ '"}|'J  
sFileName = value; < 4DWH  
} Zl]Zy}p*+  
w>I>9O}(`  
]pLQ;7f7D  
public int getNSplitter() cmDskQ:  
{ E-,74B&H  
return nSplitter; A.9,p  
} H[o'j@0  
&]~z-0`$!  
@+",f]  
public void setNSplitter(int nCount) ,x5`5mT3  
{ sr\lz}JW  
nSplitter = nCount; STgl{#  
} Kb0OauW  
} a/+tsbw  
"s$v?voo  
1Giy|;2/  
/* L K9vvQz  
**Utility.java 52B ye   
*/ hCO*gtA)M  
package NetFox; oS)0,p  
zypZ3g{vz  
gf+Kr02~  
public class Utility { 5EIhCbA  
^SCZ  
`>RJ*_aKEI  
public Utility() <\x/Y$jm0n  
{ cHK)e2 r  
U{D ?1tF  
F#_7mC   
} JJ56d)37.  
XF2u<sDe  
//线程睡眠 &0TOJ:RP  
public static void sleep(int nSecond) )8oI  s  
{ wgSA6mQZ  
try{ ,_`\c7@  
Thread.sleep(nSecond); KdF QlQaj  
} @Z!leyam  
catch(Exception e) zQ xZR}'  
{ AO;`k]0e  
e.printStackTrace (); ZZTPAmIr  
} _,b%t1v  
} T3['6%  
3y>.1  
//日志 u*[,W-R&  
public static void log(String sMsg) KtHh--j`  
{ D_O%[u}  
System.err.println(sMsg); I"3Qdi  
} ?)Lktn9%  
TJ`E/=J!  
lfu1PCe5  
public static void log(int sMsg) ^BjwPh4Z#  
{  DVD}  
System.err.println(sMsg); ~!]FF}6  
} J{$C}8V  
} !.L%kw7z  
[7]p\' j  
|LKhT4rE  
/* }.gDaxj  
**TestMethod.java ;: Hfkyy]  
*/ {a_= 4a  
package NetFox; z>k6T4(  
 >0+m  
133lIX+(k  
public class TestMethod { {i^ ?XdM  
y VQ qz  
`a:@[0r0U  
public TestMethod() 2U>1-p&dn  
{ ///xx/weblogic60b2_win.exe iUA2/ A  
try{ >;o^qi_$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *P:`{ZV7=W  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [x!T<jJ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,{itnKJC  
fileFetch.start(); Dc oTa-~  
} 3Q[]lFJ}F  
catch(Exception e){e.printStackTrace ();} M O* m@  
s;}';#  
Mim 9C]h(  
} e@p` -;<  
hr@KWE`  
 'm}~  
public static void main(String[] args) xm~ff+(&@S  
{ M6 AQ8~z  
new TestMethod(); s\o </ZDo  
} gbr|0h>  
} S7wZCQe  
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