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http断点续传简单实现(java)

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/* 83Q 4On  
**SiteFileFetch.java RWg No #<  
*/ k|lcc^[0  
package NetFox; }DK7'K  
import java.io.*; znaUBv_  
import java.net.*; 8\5 T3AF  
yl1gx  
b{]z w pf  
public class SiteFileFetch extends Thread { Dm-zMCf}Q  
I/L_@X<*r  
7w/4QiI  
SiteInfoBean siteInfoBean = null; //文件信息Bean pnbIiyV  
long[] nStartPos; //开始位置 wT:b\km:!  
long[] nEndPos; //结束位置 t-0a7 1#e  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -< &D  
long nFileLength; //文件长度 L&%s[  
boolean bFirst = true; //是否第一次取文件 !VI]oRgP  
boolean bStop = false; //停止标志 D IzH`|Y  
File tmpFile; //文件下载的临时信息 b+&% 1C  
DataOutputStream output; //输出到文件的输出流 tjluk  
A#95&kJpy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) i*NH'o/  
public SiteFileFetch(SiteInfoBean bean) throws IOException X  .5aMm  
{ fvF?{k>~}  
siteInfoBean = bean; ( 8c9 /7h  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); +L9Eqll  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); jg\Z;_!W  
if(tmpFile.exists ()) =aoMii   
{ A3iFI9Iv  
bFirst = false; }`,t$NV`  
read_nPos(); "huFA|`  
} dK2p7xo  
else 4*cU<  
{ #[`:'e  
nStartPos = new long[bean.getNSplitter()]; vWf; 'j  
nEndPos = new long[bean.getNSplitter()]; < VSA  
} jhg;%+KB  
?)1{)Erf8x  
U}PiY"S<  
_G.>+!"2/  
} UM6(s@$  
s8#X3Rp  
*UmI]E{g3(  
public void run() ktdW`R\+  
{ @p NNq  
//获得文件长度 WUsKnf  
//分割文件 371 TvZ4  
//实例FileSplitterFetch pFHz"]  
//启动FileSplitterFetch线程 9uBM<  
//等待子线程返回 ~(IB0=A{v  
try{ i2&ed_h<?  
if(bFirst) _cJ2\`M  
{ -cSP _1  
nFileLength = getFileSize(); LM-J !44  
if(nFileLength == -1) hijgF@  
{ GrAujc5|  
System.err.println("File Length is not known!"); p n.T~"%  
} '_/Bp4i  
else if(nFileLength == -2) fmiz,$O4?  
{ x>*Drm 7  
System.err.println("File is not access!"); v!ujj5-$I  
} yzLpK;  
else JMz;BAHT  
{ ^,;z|f'% *  
for(int i=0;i<nStartPos.length;i++) Tp_L%F  
{ KFvQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); j;fpQ_KL  
} .%Ta]!0  
for(int i=0;i<nEndPos.length-1;i++) X~<("  
{ *EZHJt9  
nEndPos = nStartPos[i+1]; U 9A~9"O  
} ZOQTINf  
nEndPos[nEndPos.length-1] = nFileLength; /s[l-1zW  
} *i- _6s  
} f/Hm{<BY  
0;:.B j  
cnFI &,FM  
//启动子线程 /`6ZAo m9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "gne_Ye.  
for(int i=0;i<nStartPos.length;i++) qLT>Mz)$ %  
{ 3`ELKq  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `^FGwx@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bV$)!]V  
nStartPos,nEndPos,i); YH%'t= <m  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D[mSmpjE6&  
fileSplitterFetch.start(); OVko+X`  
} tdSfi<y5I  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ar:*oiU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !2'jrJGc  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L?Qg#YSd ~  
nEndPos = " + nFileLength); ( |PAx (  
// fileSplitterFetch[nPos.length-1].start(); \CXQo4P  
3`B6w$z>(  
n;$5Cq!v=  
//等待子线程结束 QzzW x2  
//int count = 0; " 9^j.  
//是否结束while循环 "E8zh|m o  
boolean breakWhile = false; J]G?Rc  
1!1 beR]  
&b?LP]   
while(!bStop) ALNc'MW!  
{ -Gw$#!  
write_nPos(); 1QU:?_\6@t  
Utility.sleep(500); <X7FMNr[  
breakWhile = true; Jnna$6G)B  
L\&<sy"H  
Sk:ws&D1u  
for(int i=0;i<nStartPos.length;i++) t0nI('LX,  
{ T:IW%?M  
if(!fileSplitterFetch.bDownOver) e=Z, Jg  
{ Sz^5b!  
breakWhile = false; ;z IP,PMM  
break; spGB)k,^  
} oA =4=`  
} qd#sY.|1  
if(breakWhile) p"FW&Q=PN  
break; C#t'Y*  
sm\f0P!rv  
|pmZ.r  
//count++; LwK+:4$  
//if(count>4) (q4),y<:[  
// siteStop(); t@R ?Rgu3  
} -GqT7`:(H4  
ltgc:&=|@  
n%k!vJ)]  
System.err.println("文件下载结束!"); %c [F;ug  
} BwBm[jtP  
catch(Exception e){e.printStackTrace ();} YQpSlCCo 3  
} h~p>re  
Yb /i{@AJ  
md q;R*`  
//获得文件长度 qnoNT%xazo  
public long getFileSize() {.De4]ANh  
{ CMCO}#  
int nFileLength = -1; z%e8K(  
try{ ~5 *5  
URL url = new URL(siteInfoBean.getSSiteURL()); 3q'&j, ,^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rc/nFl 6#  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8:#rA*Y  
Pp| *J^U 4  
}yJ$SR]t  
int responseCode=httpConnection.getResponseCode(); -,+q#F  
if(responseCode>=400) CWNx4)ZGw  
{ 8S<@"v  
processErrorCode(responseCode); B?)@u|0  
return -2; //-2 represent access is error @E-\ J7 yh  
} m^#rB`0;L  
d ,Y#H0`  
&CIVL#];e  
String sHeader; un=2}@ '  
+q)5dYRzV  
n#:N;T;\a  
for(int i=1;;i++) K\$J4~EtG  
{ :{ur{m5bX  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8Y_ol#\L  
//Utility.log(in.readLine()); 3T e^  
sHeader=httpConnection.getHeaderFieldKey(i); 9:!gI|C  
if(sHeader!=null) Z-U-N  
{ ]miy/V }5  
if(sHeader.equals("Content-Length")) 2 OwV^-OG  
{ TU GNq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hBFP1u/E'  
break; |<Gl91  
} ]Z oD'-,  
} `d[1`P1i[  
else *0}3t <5  
break; ^kgBa27  
} ~{D[ >j][  
} 8?i7U<CB  
catch(IOException e){e.printStackTrace ();} (&P9+Tl  
catch(Exception e){e.printStackTrace ();} vi|R(&  
kdCP  
v9D22,K-  
Utility.log(nFileLength); \T\b NbPn  
2{Chu85   
m1IKVa7-\}  
return nFileLength; 6sE{{,OGB  
} !p[9{U->o;  
2PeR   
-YjA+XP  
//保存下载信息(文件指针位置) \/SQ,*O  
private void write_nPos() H{AMZyV0/d  
{ E!Zx#XP1  
try{ 0z[dl Hi  
output = new DataOutputStream(new FileOutputStream(tmpFile)); d)[;e()  
output.writeInt(nStartPos.length); TeWMp6u,r  
for(int i=0;i<nStartPos.length;i++) `D":Q=:  
{ |8.(XsN  
// output.writeLong(nPos); $F/EJ>  
output.writeLong(fileSplitterFetch.nStartPos); [tH-D$V  
output.writeLong(fileSplitterFetch.nEndPos); Sje wuIi1  
} 7;tJK^J`  
output.close(); !bD@aVf?5  
} >rP#ukr5  
catch(IOException e){e.printStackTrace ();}  X!j{o  
catch(Exception e){e.printStackTrace ();} T /mI[*1xI  
} \(PohwWWo  
_kdL'x  
!{82D[5  
//读取保存的下载信息(文件指针位置) +dP L>R  
private void read_nPos() {\z({Wlb]  
{ &%2*Wu;  
try{ "&/]@)TPz  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8 :o<ry  
int nCount = input.readInt(); ,j?.4{rHJ  
nStartPos = new long[nCount]; SR8qt z/V  
nEndPos = new long[nCount]; #k$)i[aI-  
for(int i=0;i<nStartPos.length;i++) 4:sjH.u<  
{ x%<  
nStartPos = input.readLong(); ;),BW g  
nEndPos = input.readLong(); (Si=m;g  
} M@(^AK{mU  
input.close(); KYkS9_yF  
} i`0v#P  
catch(IOException e){e.printStackTrace ();} =rd|0K"(r  
catch(Exception e){e.printStackTrace ();} Jj= ;  
} O Lc}_  
Ka|eFprS  
jS!`2li?{  
private void processErrorCode(int nErrorCode) `' 153M]  
{ s3 ;DG  
System.err.println("Error Code : " + nErrorCode); e*  
} om3`[r[{  
}%-t+Tf,  
9Q!b t  
//停止文件下载 @O}7XRJ_8  
public void siteStop() $f pq 3  
{ ~aXqU#8  
bStop = true; Fa epDjY8  
for(int i=0;i<nStartPos.length;i++) TS"D]Txs  
fileSplitterFetch.splitterStop(); EQe5JFR  
E"|4Y(G  
$2MAZGJV  
} a Zk&`Jpz  
} Dw2Q 'E  
//负责部分文件的抓取 npDIX  
**FileSplitterFetch.java zD)pF1,7:8  
*/ DOQc"+  
package NetFox; !>(RK"KWq]  
OI0B:()  
@+Y8*Rj\3  
import java.io.*; =9G;PVk|  
import java.net.*; oW$s xS  
}Z`(aDH  
T}D<Sc  
public class FileSplitterFetch extends Thread { t0#[#I1+  
8seBT ;S  
f{lZKfrp  
String sURL; //File URL 6] z}#"  
long nStartPos; //File Snippet Start Position )B!d,HKt;  
long nEndPos; //File Snippet End Position A K/z6XGy  
int nThreadID; //Thread's ID 70B)|<$  
boolean bDownOver = false; //Downing is over k]rLjcB  
boolean bStop = false; //Stop identical kLS(w??T  
FileAccessI fileAccessI = null; //File Access interface tehUD&  
)2Hff.  
nd{R 9B  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;$BdP7i:  
{ DXQi-+?  
this.sURL = sURL; %g cc y|  
this.nStartPos = nStart; S*"u/b;  
this.nEndPos = nEnd; -Z^4L  
nThreadID = id; CkRX>)=py  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zQH]s?v  
} _ jAo:K_Z  
=C f(B<u  
Dz_eB"}  
public void run() DP7C?}(  
{ 3P <'F2o  
while(nStartPos < nEndPos && !bStop) [ B0K  
{ [rreFSy#@  
h7;bclU  
]$M<]w,IJ2  
try{ cUK\x2  
URL url = new URL(sURL); bO<0qM~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S^cH}-+  
httpConnection.setRequestProperty("User-Agent","NetFox"); }wSy  
String sProperty = "bytes="+nStartPos+"-"; Hh kN^S,  
httpConnection.setRequestProperty("RANGE",sProperty);  uu%?K@Qq  
Utility.log(sProperty); #^&jW  
WjM>kWv  
\h3e-)  
InputStream input = httpConnection.getInputStream(); z]Acs  
//logResponseHead(httpConnection); VG*'"y *%w  
=!ac7i\F  
f]d!hz!  
byte[] b = new byte[1024]; Jbp5'e _  
int nRead; E=/[s]@5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y~F<9;$=  
{ ^GYq#q9Q  
nStartPos += fileAccessI.write(b,0,nRead); TK>{qxt:=  
//if(nThreadID == 1) 1]\TI7/ n  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b0a}ME&1  
} L8V3BH7B  
?Ay3u^X  
(Q-I8Y8l8  
Utility.log("Thread " + nThreadID + " is over!"); qi+&|80T.  
bDownOver = true; Cj&$%sO1  
//nPos = fileAccessI.write (b,0,nRead); r(}nhUQ%E  
} K@@9:T$  
catch(Exception e){e.printStackTrace ();} >Wh3MG6  
} y67uH4&Vm  
} kd;'}x=5yP  
?An,-N-ezf  
c6b0*!D"}  
//打印回应的头信息 ZM~`Gd9K0E  
public void logResponseHead(HttpURLConnection con) el'j&I  
{ 98*x 'Wp  
for(int i=1;;i++) %{STz  
{ C=VIT*=  
String header=con.getHeaderFieldKey(i); 00M`%c/  
if(header!=null) p\U*;'hv  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DMkhbo&+  
Utility.log(header+" : "+con.getHeaderField(header)); D{AFL.r{  
else 4YJ=q% G  
break; jNy?[ )  
} /#yA%0=w  
} DzPs!(5[I  
A/Khk2-:  
wO"GtVd  
public void splitterStop() i<u9:W  
{ y3yvZD  
bStop = true; jX|=n.#q  
} Q#WE|,a  
Sl.o,W^  
Ko}2%4on  
} :pd&dg!5  
Bp0bY9xLg_  
<lOaor c  
/* (^H5EeGV{  
**FileAccess.java )!C7bTv 4  
*//文件访问(定位,写) <*Y O~S(R  
package NetFox; w4{y "A  
import java.io.*; k,X74D+  
aqfL0Rg+`  
Zu=kT}aGg  
public class FileAccessI implements Serializable{ } gkP  
b%nkIPA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9bEM#Hj  
RandomAccessFile oSavedFile; wZv-b*4  
long nPos; n+quSF)  
,#aS/+;[)  
6+ 8mV8{-8  
public FileAccessI() throws IOException \/,g VT  
{ BPWnck=%  
this("",0); l^,qO3ES  
} a RKv+{K  
k ]bPI$  
? : md  
public FileAccessI(String sName,long nPos) throws IOException @xJCn}`Zj  
{ ] SK[C" S  
oSavedFile = new RandomAccessFile(sName,"rw"); 6F`\YSn+  
this.nPos = nPos; %FlA ":W  
oSavedFile.seek(nPos); 4zzlazU  
} E0`[G]*G  
MW]8;`|jC  
Xb+3Xn0}&8  
public synchronized int write(byte[] b,int nStart,int nLen) (zmNa}-  
{ {{E jMBg{  
int n = -1; cDO:'-  
try{ C|$L6n>DR6  
oSavedFile.write(b,nStart,nLen); /:Y9sz uW`  
n = nLen; F; a3  
} l7Y8b`  
catch(IOException e) i>"dBJh]b  
{ v?%3~XoH  
e.printStackTrace (); .M+v?A d  
} &Y=.D:z<  
3`rIV*&_{  
eKJ:?Lxv;  
return n; N<"`ShCNM  
} %|jzEBz@  
/=trj5h  
1uC;$Aj6:  
} ^5>du~d  
" <*nZ~nE)  
8;8YA1@w  
/* {,F/KL^u  
**SiteInfoBean.java +',^((o  
*/ ?C~X@sq  
package NetFox; <c\]Ct  
NGj"ByVjx  
[Gf{f\O  
public class SiteInfoBean { d|3o/@k  
+l.|kkZ?  
` #=fA  
private String sSiteURL; //Site's URL v D&Kae<  
private String sFilePath; //Saved File's Path lJ'trYaq7  
private String sFileName; //Saved File's Name Ym:{Mm=ud  
private int nSplitter; //Count of Splited Downloading File S"{GlRpd  
\2Xx%SX  
Y.9~Bo<<r  
public SiteInfoBean() 08O7F  
{//nSplitter的缺省值为5 3/l\ <{  
//default value of nSplitter is 5 u6p5:oJj,  
this("","","",5); ,,}sK  
} ,wlbIl~  
1w bTqc  
($:y\,5(9I  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nIR*_<ow  
{ +h|K[=l\  
sSiteURL= sURL; E\_W  
sFilePath = sPath; v}&#f&q!  
sFileName = sName; )ZN(2z  
this.nSplitter = nSpiltter; 'jN/~I  
+/w(K,  
363cuRP  
} CvP`2S\  
O!yakU+  
r/^tzH's  
public String getSSiteURL() 0w'|d@*wV  
{ }ymc5-  
return sSiteURL; ;fj9 n-  
} rWqkdi1  
%P(;8sS  
Kc-Y  
public void setSSiteURL(String value) Gxo# !  
{ n+X1AOE[L  
sSiteURL = value;  :4{Qh  
} v8>!Gft  
o|0 '0P  
Vk WO}  
public String getSFilePath() ]u;GNz}?  
{ 90?,-6  
return sFilePath; V8\$`NEP  
} m:b^,2"g  
T ^N L:78  
-!i;7[N  
public void setSFilePath(String value) v&e-`.xR  
{ %8a=mQl1^  
sFilePath = value; j=FMYd8$y  
} Mq76]I%  
xkF$D:s P  
jzMhJ  
public String getSFileName() 7TnM4@*f  
{ ([[)Ub$U  
return sFileName; /z..5r^,ZZ  
} .r7D )xNa@  
Q6eN+i2 ;  
y{YXf! AS  
public void setSFileName(String value) }Z"28?  
{ kSB3KR;~n  
sFileName = value; "$]ls9-%n  
} -J{Dxz  
{3.*7gnY\L  
|OOXh[y  
public int getNSplitter() Td5bDO  
{ ss/h[4h4h  
return nSplitter; O<4Q$|=&?  
} 2wGF-V  
p "/(>8  
tF<^9stM  
public void setNSplitter(int nCount) #"hJpyW 4V  
{ 7[4_+Q:}  
nSplitter = nCount; ^GE^Q\&D&  
} =d}gv6v2S  
} *Yj~]E0`1  
+:fqL  
5r^1CFO  
/* Qk+=znJ  
**Utility.java W]Y@WKeT  
*/ ]cn/(U`  
package NetFox; ?]s%(R,B5  
~5FS|[1L  
txj wZ_p  
public class Utility { @bc[ eas  
Y||yzJdC  
mfu*o0   
public Utility() P4hZB_.=  
{ fL(':W&n-  
5ze`IY  
I/mvQxp  
} 0[V&8\S~'T  
(m<R0  
//线程睡眠 .=>\Qq%  
public static void sleep(int nSecond) yJF 2  
{ .Ln;m8  
try{ `l+ >iM  
Thread.sleep(nSecond); $dlnmNP+  
} gsLr=  
catch(Exception e) ov?.:M  
{ I/^q+l.=`{  
e.printStackTrace (); )w Z49>Y  
} Y8D7<V~Md  
} p.@0=)  
uo]Hi^r.l  
//日志 nu;} S!J  
public static void log(String sMsg) 30A`\+^f  
{  QpdujtH`  
System.err.println(sMsg); bc `UA  
} K?5B>dv@A  
J ZVr&KZN  
6.7`0v?,n  
public static void log(int sMsg) .tZjdNE(h  
{ 8W19#?7>B  
System.err.println(sMsg); Gojl0?  
} \?bwm&6+r  
} 1 ;_{US5FR  
aEcktg6h  
bHhC56[M  
/* OT-n\sL$  
**TestMethod.java Zk~nB}Xw  
*/ cEDDO&u  
package NetFox; "WF( 6z#  
S 23S.]r  
) 1lJ<g#  
public class TestMethod { aDm-X r  
1$:{{%  
gGtep*k  
public TestMethod() w o-O_uZB  
{ ///xx/weblogic60b2_win.exe v+xgxQGYH  
try{ :)KTZ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -D!#W%y8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IUh5r(d 68  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1$='`@8I  
fileFetch.start(); qT4I Y$h  
}  opUKrB  
catch(Exception e){e.printStackTrace ();} .nj?;).  
c[wQJc  
#,f}lV,&  
} * kX3sG$8  
|@o]X?^  
JLy)}8I  
public static void main(String[] args) w5dI k]T  
{ d8Q_6(Ar|  
new TestMethod(); XBfiaj  
} ,W)IVc   
} q|47;bK'  
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