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http断点续传简单实现(java)

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/* j*:pW;)^  
**SiteFileFetch.java *u{.K:.I  
*/ M9OFK\)  
package NetFox; 4l`gAE$  
import java.io.*; G[>-@9_b  
import java.net.*; <7] z'  
nG%j4r ;  
VD#^Xy4% r  
public class SiteFileFetch extends Thread { !d0@^JbM"  
Xp?Z;$r$  
a@jP^VVk  
SiteInfoBean siteInfoBean = null; //文件信息Bean 49zp@a  
long[] nStartPos; //开始位置 }\*Sf[EMD  
long[] nEndPos; //结束位置 dw4)4_  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +tN-X'u##  
long nFileLength; //文件长度 uATBt   
boolean bFirst = true; //是否第一次取文件 (P>vI'  
boolean bStop = false; //停止标志 +%Gm2e;_u  
File tmpFile; //文件下载的临时信息 gwYd4  
DataOutputStream output; //输出到文件的输出流 ^ KjqS\<  
X*yl% V  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) z0W+4meoH  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4 z`5W,  
{ XbOL/6V ^[  
siteInfoBean = bean; hB+ t pa  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); |}|;OG  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9,c>H6R7  
if(tmpFile.exists ()) HYH!;  
{ ?3Fo:Z`@F  
bFirst = false; 4#YklVm  
read_nPos(); si;]C~X*  
} d?P aZz{4  
else I.<#t(io  
{ ;hZ@C!S:  
nStartPos = new long[bean.getNSplitter()]; 5nn*)vK {  
nEndPos = new long[bean.getNSplitter()]; Bm7GU`j"  
} -?'CUm*Od  
"}EbA3  
XHg %X  
<FK><aA_i*  
} ,i,=LGn  
nJya1AH;  
Z7/dRc   
public void run() W*m[t&;  
{ uSQ*/h-<)0  
//获得文件长度 s?E:]  
//分割文件 X m3t xp#  
//实例FileSplitterFetch mC7Y *  
//启动FileSplitterFetch线程 Wd}mC<rv1  
//等待子线程返回 )pLq^j  
try{ >`uSNY"tO  
if(bFirst) W Q&<QVK  
{ $S}x'F!4_  
nFileLength = getFileSize(); ZkJM?Fzq  
if(nFileLength == -1) IXN4?=)I  
{ xVyUUzXs  
System.err.println("File Length is not known!"); | <*(`\ 'w  
} A!kyga6F5  
else if(nFileLength == -2) Mt Z(\&~  
{ QBy*y $  
System.err.println("File is not access!"); D=>^m=?0  
} +;Gl>$  
else ~e+w@ lK  
{ Q=8 cBRe  
for(int i=0;i<nStartPos.length;i++) u3:Qt2^S  
{ ,')bO*N g  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -!cAr <  
} b9N4Gr  
for(int i=0;i<nEndPos.length-1;i++)  o %%fO  
{ ^!qmlx*  
nEndPos = nStartPos[i+1]; 0)]1)z(P  
} kk'w@Sn.(  
nEndPos[nEndPos.length-1] = nFileLength; n:D*r$ C|p  
} ,Tl5@RN  
} .[fz x`  
3>" h*U#  
$rEd5W&d!  
//启动子线程 jZ!JXmVV  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eLny-.i ,7  
for(int i=0;i<nStartPos.length;i++) 0Y 2^}u@5  
{ [BBKj)IK  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F/SsiUBS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e;5Lv9?C8  
nStartPos,nEndPos,i); 0AKwZ' &H  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E3skC%}  
fileSplitterFetch.start(); |mmG s  
} He!!oKK>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A*~1Uz\t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lKUm_; m  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %},G(>  
nEndPos = " + nFileLength); \2xBOe-a]  
// fileSplitterFetch[nPos.length-1].start(); J\'5CG  
rb'GveW[  
jSYg\ Z5!  
//等待子线程结束 Ib8i#DV  
//int count = 0; R TUNha^<T  
//是否结束while循环 \q|PHl  
boolean breakWhile = false; qo- F9u1J  
f](uc(8Z  
:5{@*  
while(!bStop) k)V%.Eobf  
{ U]0)$OH5e  
write_nPos(); \]A;EwC4C  
Utility.sleep(500); _vV&4>  
breakWhile = true; vqOLSE"t*O  
~!F4JRf  
5I1J)K;  
for(int i=0;i<nStartPos.length;i++) \{zAX~k6  
{ bV*zMoD#  
if(!fileSplitterFetch.bDownOver) A9Wqz"[  
{ vfUfrk@D~  
breakWhile = false; Gc!8v}[7J  
break; s;7qNwYO  
} %*c|[7Z~V  
} (iOCzZ6S  
if(breakWhile) dMmka  
break; -Q PWi2:k  
u7&'3ef  
5MY}(w  
//count++; ;nKHm  
//if(count>4) B8AzN9v&"N  
// siteStop(); SM+fG:4d  
} kdh9ftm*\  
@1?]$?u&  
[Cqqjv;_  
System.err.println("文件下载结束!"); uQ]]]Z(H'  
} 36x:(-GFq  
catch(Exception e){e.printStackTrace ();} !5%5]9'n@*  
} asN }  
$>ZP%~O  
s.^9HuM  
//获得文件长度 hdtnC29$  
public long getFileSize() \41)0,sEy  
{ 2{B(j&{  
int nFileLength = -1; |8c:+8  
try{ prEu9$:t  
URL url = new URL(siteInfoBean.getSSiteURL()); rk,1am:cg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g~c|~u(W  
httpConnection.setRequestProperty("User-Agent","NetFox"); Tj21YK.mk  
&s^>S? L-  
Ogke*qM  
int responseCode=httpConnection.getResponseCode(); %y\eBfW,/  
if(responseCode>=400) 72ViPWW  
{ Kq 4<l  
processErrorCode(responseCode); n_aNs]C9R  
return -2; //-2 represent access is error ^b!7R <>~  
} mH*@d"  
2Uv3_i<  
(vAv^A*i}  
String sHeader; |1+(Ny.%k  
L> Oy7w)Y  
gJ5wAK+?  
for(int i=1;;i++) bV$8 >[`  
{ +#qt^NO  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Bf:tal6 -M  
//Utility.log(in.readLine()); i<wU.JX&h  
sHeader=httpConnection.getHeaderFieldKey(i); B >u,)  
if(sHeader!=null) MkW1FjdP  
{ ,+/9K)X  
if(sHeader.equals("Content-Length")) { w8 !K  
{ ]\RSHz  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); { LT4u ]#  
break; Z-t}6c'Kg  
} :-u-hO5*8  
} `e?;vA&  
else G?1x+H;o5  
break; qTTn51  
} 9R@abm,I  
} ~+<xFi  
catch(IOException e){e.printStackTrace ();} 2#b<d?"  
catch(Exception e){e.printStackTrace ();} dT]L-uRZgy  
!jAWNK6  
jj3Pf>D+k  
Utility.log(nFileLength); Q&upxE4-~  
<DXmZ1  
D#d8^U  
return nFileLength; j!S1Y0CV  
} w`j*W$82  
[T4 pgt'H  
V Z2.w4b  
//保存下载信息(文件指针位置) Bzu(XQ  
private void write_nPos() /1 US,  
{ V9zywM  
try{ ?..i4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]PlY}VOY  
output.writeInt(nStartPos.length); mX@j  
for(int i=0;i<nStartPos.length;i++) mNx,L+ 3  
{ jy!f{dsC  
// output.writeLong(nPos); Eg`R|CF  
output.writeLong(fileSplitterFetch.nStartPos); }$|%/Y  
output.writeLong(fileSplitterFetch.nEndPos); JN&MyA"  
} m)@Q_{=6M  
output.close(); Mr=}B6`  
} N a. nA  
catch(IOException e){e.printStackTrace ();} KP=D! l&q  
catch(Exception e){e.printStackTrace ();} t&R!5^R  
} n9kd2[s|  
|7QVMFZ  
E 4='m  
//读取保存的下载信息(文件指针位置) n5egKAgA  
private void read_nPos() qSEB}1  
{ 66~e~F}z  
try{ wX)efLmyhY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $/[Gys3"  
int nCount = input.readInt(); 3`&VRF8  
nStartPos = new long[nCount]; e{fZ}`=7y  
nEndPos = new long[nCount]; W>Mse[6`c  
for(int i=0;i<nStartPos.length;i++) \;-=ODC  
{ N<aB)</  
nStartPos = input.readLong(); d&aBs++T  
nEndPos = input.readLong(); #D`S  
} S)"##-~`T  
input.close(); ;Ze"<U  
} 5jn$7iE`  
catch(IOException e){e.printStackTrace ();} ?CH?kP  
catch(Exception e){e.printStackTrace ();} 0NQ7#A  
} {A]k%74-a  
4ef*9|^x#  
a9#W9eP  
private void processErrorCode(int nErrorCode) 2f3=?YqD  
{ v7 8&[  
System.err.println("Error Code : " + nErrorCode); *>e~_{F  
} |x d@M-ln  
j:HH#U  
nU} ~I)@V  
//停止文件下载 K4j@j}zK9I  
public void siteStop() qs!>tw  
{ kF+ZW%6N  
bStop = true; ra]!4Kd'  
for(int i=0;i<nStartPos.length;i++) Q&u>7_, Du  
fileSplitterFetch.splitterStop(); Az U|p  
'"` Lv/  
968Ac}OA  
} 4)c+t"h  
} D3%l4.h  
//负责部分文件的抓取 T@(6hEmP,  
**FileSplitterFetch.java PSW #^o  
*/ R'G'&H{N  
package NetFox; xik`W!1S  
}  c{Fa&  
=a?a@+  
import java.io.*; gWFL  
import java.net.*; UskZ%J  
/GsSrP_?]  
}US7 N w  
public class FileSplitterFetch extends Thread { uyL72($  
&}zRH}s;  
=MMCf0  
String sURL; //File URL HS{P?~:=U  
long nStartPos; //File Snippet Start Position G3H#XK D  
long nEndPos; //File Snippet End Position HjV\lcK:v  
int nThreadID; //Thread's ID *I=_*LoG2  
boolean bDownOver = false; //Downing is over azvDvEWCQZ  
boolean bStop = false; //Stop identical N\_( w:q  
FileAccessI fileAccessI = null; //File Access interface "YuZ fL`bb  
dO+kPC  
7k 3p'FeS  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LL{t5(- _  
{ PdR >;$1  
this.sURL = sURL; Qqp)@uM^  
this.nStartPos = nStart; PT mf  
this.nEndPos = nEnd; 6yN" l Q7  
nThreadID = id; %h0D)6 j  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Am#m>^!qb  
} c+1vqbqHG  
LlU' _}>  
'#H&:Htm;L  
public void run() GUKDhg,W  
{ wjuGq.qIu  
while(nStartPos < nEndPos && !bStop) f](I.lm:  
{ !0b%Jh  
?4:rP@  
6%>/og\%  
try{ _~ v-:w  
URL url = new URL(sURL); !2(.$}E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cq gJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); yP x\ltG3  
String sProperty = "bytes="+nStartPos+"-"; ]+AAT=B<!  
httpConnection.setRequestProperty("RANGE",sProperty); Y]~IY?I  
Utility.log(sProperty); Bk+{}  
H]BAW *}  
SAP;9*f1\  
InputStream input = httpConnection.getInputStream(); 8AryIgy>@  
//logResponseHead(httpConnection); #`vVg GZ&  
658\#x8|  
p[u4,  
byte[] b = new byte[1024]; C+`xx('N9  
int nRead; .XIr?>G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) THJ 3-Ug  
{ Ax f^hBP  
nStartPos += fileAccessI.write(b,0,nRead); l7ZB3'  
//if(nThreadID == 1) Ex 6o=D2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @2u#93Y  
} D{>\-]\  
t7&Dwmck9  
sqT^t!  
Utility.log("Thread " + nThreadID + " is over!"); 3#9uEDdE  
bDownOver = true; RXM}hqeG  
//nPos = fileAccessI.write (b,0,nRead); WI6(#8^p  
} >ZX|4U[$P  
catch(Exception e){e.printStackTrace ();} jSB'>m]  
} 1ADv?+j)A/  
} ^L ]B5,} -  
NK~PcdGl  
k9 l^6#<?  
//打印回应的头信息  *=TYVM9  
public void logResponseHead(HttpURLConnection con) xLZ bU4  
{ ZlrhC= 0  
for(int i=1;;i++) s*f1x N<  
{ qT$ )Rb&  
String header=con.getHeaderFieldKey(i); Y5n>r@ )m  
if(header!=null) c88_}%h?(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8|6~o.B.G  
Utility.log(header+" : "+con.getHeaderField(header));  f -7S:,  
else >zFD $  
break; Y!M~#oqio  
} 6i| ~7md,  
} w?_`/oqd|  
O)`Gzx*ShU  
.wD>Gs{sH[  
public void splitterStop() }Fm\+JOS   
{ L $SMfx  
bStop = true; 7u|%^Ao6  
} [ T-*/}4$  
bH,M,xIL2  
s@PLS5d"  
} j-QGOuvW  
Wa<-AZnh  
D&-vq,c  
/* e:BDQU  
**FileAccess.java c`ftd>]  
*//文件访问(定位,写) :s]\k%"  
package NetFox; **n y!  
import java.io.*; )%t7\1)B3  
:WO{xg  
e+{BJN vz  
public class FileAccessI implements Serializable{ lA]N04 d  
_CL{IY  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qW3x{L$c  
RandomAccessFile oSavedFile; }1Z6e[K?  
long nPos; tJAnuhX  
L?Cjo4xS  
l/ QhD?)9  
public FileAccessI() throws IOException &y\igX1  
{ (Igu:=  
this("",0); #n#HzbT  
} 9OfU7_m  
9>;} /*:H  
ZL,8,;]  
public FileAccessI(String sName,long nPos) throws IOException [1U{ci&=p  
{ "O``7HA}  
oSavedFile = new RandomAccessFile(sName,"rw"); y] y9'5_  
this.nPos = nPos; Hr&Ere8.4p  
oSavedFile.seek(nPos); E?_ zZ2  
} Wt:~S/l  
+<{m45  
%i595Ij-]  
public synchronized int write(byte[] b,int nStart,int nLen) a5 bPEJ=I  
{ Cdmy.gx^  
int n = -1; :]-$dEu&  
try{ KGD'mByt"  
oSavedFile.write(b,nStart,nLen); w,/6B&|  
n = nLen; mqw 84u  
} \C7q4p?8  
catch(IOException e) zIm-X,~I$  
{ pZjpc#*9N  
e.printStackTrace (); =9<$eLE0  
} \?d TH:v/E  
nd.hHQ  
7 OWsHlU  
return n; *E7R(#,yC  
} ,_bp)-OG  
xh r[ A  
}#bZ8tm&  
} 7O$ &  
>4c`UW  
&oEyixe  
/* %N1"* </q  
**SiteInfoBean.java djGs~H>;U_  
*/ cWM:  
package NetFox; 5NFRPGYX  
a%*_2#  
0MrN:M2B  
public class SiteInfoBean { ^vM_kAr A  
1]Lh'.1^  
P7UJ-2%Y+  
private String sSiteURL; //Site's URL x0ne8NDP  
private String sFilePath; //Saved File's Path Why"G1`  
private String sFileName; //Saved File's Name f"P$f8$  
private int nSplitter; //Count of Splited Downloading File ]!faA\1  
Zw24f1iY  
8i[LR#D)  
public SiteInfoBean() N|<bVq%  
{//nSplitter的缺省值为5 [T]Bfo  
//default value of nSplitter is 5 5k~\or 5_  
this("","","",5); m9!DOL1pl  
} A_F0\ EN*  
}*Zo6{B-  
- wWRm  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B\0t&dai|'  
{ Eu4 &-i  
sSiteURL= sURL; zi.mq&,]R  
sFilePath = sPath; x`L+7,&n  
sFileName = sName; E-F5y  
this.nSplitter = nSpiltter; WUY,. 8  
RY<%'\A`~  
[xf$VkjuF  
} `M0YAiG  
( OXY^iq  
 p[Hr39o  
public String getSSiteURL() Fv@tD4I>  
{ 6klD22b2$  
return sSiteURL; HzEGq,.  
} ^/<|f,2  
)# PtV~64  
=y<0UU  
public void setSSiteURL(String value) j%WY ,2P  
{ Ro~fvL~Ps  
sSiteURL = value; 10O3Z9  
} 63C(Tp"  
PkO!'X  
ll2Vk*xs  
public String getSFilePath() ZRP y~wy>  
{ j.B>v\b_3  
return sFilePath; f~R[&q +  
} 0R4akLW0  
&~ y{'zoL  
*v&*% B  
public void setSFilePath(String value) }H2#H7!H  
{ 8JP6M!F#  
sFilePath = value; FJF3B)Va|  
} ~QCA -Yud  
RJwb@r<v  
8$m1eQ`{  
public String getSFileName() b}}y=zO|$  
{ v8  
return sFileName; \OA L Or  
} vnZ4(  
dE GX3 -  
& +]x;K  
public void setSFileName(String value) }PmTR4F!}  
{ o X@nP?\  
sFileName = value; N3Z@cp  
} yf?W^{^|  
^}hZ'<PK  
I{EIHD<  
public int getNSplitter() ?b"Vj+1:x  
{ m/{Y]D{2  
return nSplitter; ,ex]$fQ'  
} 1J&#&\,f&  
BCBUb  
#fN/LO  
public void setNSplitter(int nCount) L^)qe^%3  
{  C/  
nSplitter = nCount; zhjJ>d%w  
} zWtj|%ts  
} 9cz)f\  
zuMO1s  
7j T#BWt  
/* E[ 0Sst x  
**Utility.java _jo$)x+'x  
*/ oSmjs  
package NetFox; <"A#Eok|4  
wx./"m.M  
WAv@F[  
public class Utility { ?Nu#]u-  
NZfd_? 3  
'QR4~`6I  
public Utility() ET3 ,9+Gj  
{ j3LNnZY  
0R*}QXph  
NN11}E6  
} GZS{&w!  
ey*,StT5a  
//线程睡眠 77tZp @>hn  
public static void sleep(int nSecond) ]`K[W&  
{ <ZV7|'^  
try{ WSS(Bm|B  
Thread.sleep(nSecond); sSV^5  
} H6{Rd+\Z  
catch(Exception e) QY =QQG  
{ Yx!n*+:J  
e.printStackTrace (); 'z~KTDX  
} N" ;^S  
} g4Bg6<;  
}-dF+m:  
//日志 v|>BDN@,6  
public static void log(String sMsg) tpE3|5dZF  
{ =uS8>.Qj  
System.err.println(sMsg); TtZrttCE6  
} 7F~xq#Wi#  
j~.u>4  
jWhD5k@v  
public static void log(int sMsg) yG4MUf6  
{ F; 0Dp  
System.err.println(sMsg); ^&HI +M  
} X!m;uJZp  
} oR7 7`  
u$\Tg3du2  
~O8] 3+U  
/* >H8^0n)?  
**TestMethod.java |]I#CdO  
*/ ,d5ia4\K  
package NetFox; nMeSCX  
I ;l`VtD  
fq{I$syY  
public class TestMethod { 2AmR(vVa"  
(Y&R0jt  
=w t-YM  
public TestMethod() JLt{f=`%F  
{ ///xx/weblogic60b2_win.exe L-SdQTx_  
try{ ]2g5Ka[>w  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X9SJ~n  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aL{EkiR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5t TLMZ`o  
fileFetch.start(); j_hjCQ  
} oA[2)BU  
catch(Exception e){e.printStackTrace ();} - f+CyhR"*  
k#BU7Exij  
uLF\K+cz  
} 3$;J0{&[i  
N c9<X  
Ogn,1nm%  
public static void main(String[] args) oK%K+h  
{ /]P%b K6B  
new TestMethod(); 3KbUHSx  
} ~rp.jd 0l  
} >Y44{D\`  
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