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http断点续传简单实现(java)

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/* ^n1%OzGK#  
**SiteFileFetch.java =,y |00l  
*/ {q%Sx*k9[  
package NetFox; {@W93=Vq8  
import java.io.*; .Jx9bIw  
import java.net.*; h RC  
1Xu?(2;NF  
8:=n*  
public class SiteFileFetch extends Thread { Z@a9mFI?  
E/M_lvQ  
KRAcnY;u  
SiteInfoBean siteInfoBean = null; //文件信息Bean =GlVccc  
long[] nStartPos; //开始位置 Ub1hHA*)  
long[] nEndPos; //结束位置 %`MQmXgM  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #Z+i~t{e(  
long nFileLength; //文件长度 <"N_j]wD  
boolean bFirst = true; //是否第一次取文件 s m,VYYs  
boolean bStop = false; //停止标志 4y:]DC"  
File tmpFile; //文件下载的临时信息 kOO Gw:/  
DataOutputStream output; //输出到文件的输出流 -l~Z0U>^  
W%<LTWOc  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 2. G=8:l  
public SiteFileFetch(SiteInfoBean bean) throws IOException N|N3x7=gs  
{ MP Z3D9  
siteInfoBean = bean; v ^[39*8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); F{06 _T  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {]_uMg#!  
if(tmpFile.exists ()) ;~fT,7qBah  
{ 3@+b }9s8  
bFirst = false; hu_ ^OlF  
read_nPos(); [x=jH>Y  
} Kl7WQg,XOi  
else PyVC}dUAX  
{ %^sTU4D5  
nStartPos = new long[bean.getNSplitter()]; 1"Z@Q`}  
nEndPos = new long[bean.getNSplitter()]; [(X y.L7x  
} 'c2W}$q  
De7T s  
=4V&*go*\  
ZkL8e  
} dQoYCS}IaV  
4[Z\ ?[  
glDcUCF3  
public void run() v+p {|X-  
{ 0a8/B>  
//获得文件长度 {3;AwhN0H  
//分割文件 &'cL%.  
//实例FileSplitterFetch vEf4HZ&w  
//启动FileSplitterFetch线程 hfpJ+[  
//等待子线程返回 XL#[ %X9  
try{ GjoIm?  
if(bFirst) #^m0aB7r  
{ =q N2Xg/  
nFileLength = getFileSize(); D\IjyZ-O  
if(nFileLength == -1) SJD@&m%?[  
{ 9T#;,{VQ  
System.err.println("File Length is not known!"); P96pm6H_;  
} +]=e;LN$0  
else if(nFileLength == -2) zvABU+{jD  
{ fYKOJ5f  
System.err.println("File is not access!"); C{TA.\   
} hxce\OuU0h  
else %ZHP2j %~  
{  "KcA  
for(int i=0;i<nStartPos.length;i++) n>@oBG)!  
{ W3`>8v1?o  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); pv| Pm  
} f{SB1M   
for(int i=0;i<nEndPos.length-1;i++) @`\VBW  
{ (&/2\0QV  
nEndPos = nStartPos[i+1]; }VDqj}is  
} wFG3KzEq ~  
nEndPos[nEndPos.length-1] = nFileLength; *s@Qtgu  
} U qG .:@T  
} +`3!I  
V_plq6z  
+ QQS={  
//启动子线程 06jqQ-_`h  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  hi g2  
for(int i=0;i<nStartPos.length;i++) * #TUGfwy  
{ .<kqJ|SVi  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KNH1#30 K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v<Bynd-  
nStartPos,nEndPos,i); u2 `b'R9  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2]%h$f+  
fileSplitterFetch.start(); Bl=tYp|a  
} 9UvXC)R1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eQQ>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^CwR!I.D}4  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [+qCs7'  
nEndPos = " + nFileLength); v[Kxja;  
// fileSplitterFetch[nPos.length-1].start(); g{5A4|_7  
>X*Mio8P#  
sz9L8f2  
//等待子线程结束 CI3XzH\IX*  
//int count = 0; `/Y{ l  
//是否结束while循环 yf&7P;A  
boolean breakWhile = false; <&)v~-&O  
@&[T _l  
'\jd#Kn'h  
while(!bStop) {Zp\^/  
{ as J)4ema  
write_nPos(); L(X6-M:  
Utility.sleep(500); KK@.~'d  
breakWhile = true; N!*_La=TuH  
`^lYw:xA  
S_~z-`;h!  
for(int i=0;i<nStartPos.length;i++) qCv20#!"|  
{ :;t #\%L/  
if(!fileSplitterFetch.bDownOver) uc|45Zxt  
{ xe/(  
breakWhile = false; {rcnM7 S1L  
break; =y=cW1TG  
} }NsUnbxT  
} 4H@Wc^K  
if(breakWhile) |HZTN"  
break; pmX#E  
T?4G'84nN  
8i?l02  
//count++; .7n\d55a  
//if(count>4) *Vho?P6y\Y  
// siteStop(); y-CX}B#j  
} "?| > btr  
o/ui)U_   
Y#g4$"G9  
System.err.println("文件下载结束!"); \W%UZs  
} id$Ul?z8  
catch(Exception e){e.printStackTrace ();} 02Ia2e.f  
} L\;6y*K  
7 [g/TB  
P6MRd/y |  
//获得文件长度 gzeQ|m2]  
public long getFileSize() >MPr=W%E  
{ g[w,!F  
int nFileLength = -1; JgHM?AWg|  
try{ `U2DkY&n  
URL url = new URL(siteInfoBean.getSSiteURL()); -j&Tc` j_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ['ksP-=  
httpConnection.setRequestProperty("User-Agent","NetFox"); KoS*0U<g6  
[d* ~@P  
_v* nlc  
int responseCode=httpConnection.getResponseCode(); v!%5&: c3  
if(responseCode>=400) %Ts PyiYl  
{ [CAR[ g&  
processErrorCode(responseCode); Q:$Zy  
return -2; //-2 represent access is error $Y 7c  
} {W##^L~  
X6^},C'E.:  
^ :F.  
String sHeader; S(7ro]U9  
. BiCBp<  
Q);n<Z:X~  
for(int i=1;;i++) GIAc?;zY  
{ BATG FS&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E#s)52z=B  
//Utility.log(in.readLine()); d:F @a  
sHeader=httpConnection.getHeaderFieldKey(i); hUm'8)OJ  
if(sHeader!=null) d[;.r  
{ w4fW<ISg  
if(sHeader.equals("Content-Length")) +kFxi2L6  
{ ,6r{VLN  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B*E2.\~  
break; i<(Xr  
} Dr6A ,3B  
} bBY^+c<  
else `8FUX= Sh  
break; ZNx$r]4nF  
} T,$WlK Wj  
} kCXdGhb  
catch(IOException e){e.printStackTrace ();} `l*;t`h  
catch(Exception e){e.printStackTrace ();} I<A6Z&*un  
tlA"B{7  
gR@C0  
Utility.log(nFileLength); 'ky b\q  
n6k9~"?  
wM|" I^[  
return nFileLength; `~cuQ<3Tn  
} 1nu^F,M  
}@r{?8Ru  
Ve 4u +0  
//保存下载信息(文件指针位置) )Jv[xY~  
private void write_nPos() kkK kf'  
{ t>H`X~SR?  
try{ -@ZiS^l  
output = new DataOutputStream(new FileOutputStream(tmpFile)); mRZ :ie  
output.writeInt(nStartPos.length); ]f1{n  
for(int i=0;i<nStartPos.length;i++) YX*Qd$chZ  
{ OaL\w D^  
// output.writeLong(nPos); 7h)iu9j  
output.writeLong(fileSplitterFetch.nStartPos); qL94SW;  
output.writeLong(fileSplitterFetch.nEndPos); b pv= %  
} m:hY`[ f6  
output.close(); ''|#cEc)  
} C2{lf^9:&  
catch(IOException e){e.printStackTrace ();} D0N9Ksq  
catch(Exception e){e.printStackTrace ();} pn*3\  
} Q#EP|  
Sv;_HZ  
m%PC8bf`S  
//读取保存的下载信息(文件指针位置) l|hUw  
private void read_nPos() #A8@CA^d  
{ P/`I.p;  
try{ 4GB7A]^E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5?Wto4j  
int nCount = input.readInt(); gI8Bx]  
nStartPos = new long[nCount]; tbO H#|  
nEndPos = new long[nCount]; [7 YPl9  
for(int i=0;i<nStartPos.length;i++) Dn>%%K@0  
{ ,[A'tUl _  
nStartPos = input.readLong(); CwX Z  
nEndPos = input.readLong(); v|E"[P2e  
} 'u` .P:u?  
input.close(); {%#)5l)  
} 7G)H.L)$m"  
catch(IOException e){e.printStackTrace ();} PoIl>c1MS  
catch(Exception e){e.printStackTrace ();} 1$*%"5a  
} b2@VxdFN  
NuU9~gSQ  
X(7qZ P~  
private void processErrorCode(int nErrorCode) (mlzg=szW  
{ )3h^Y=43  
System.err.println("Error Code : " + nErrorCode); !s@Rok  
} Dk5Zh+^  
%e@HZ"V  
|!F5.%PY  
//停止文件下载 A?G^\I~v  
public void siteStop() !yhh8p3  
{ aAy'\T$x.  
bStop = true; |T{C,"9y  
for(int i=0;i<nStartPos.length;i++) 6&bIXy  
fileSplitterFetch.splitterStop(); !a~`Bs$'jr  
i%6;  
SIKOFs  
} xTGxvGv8  
} z%/N!RLW  
//负责部分文件的抓取 smm]6  
**FileSplitterFetch.java ]!IVz)<E&  
*/ }(<%`G6N  
package NetFox; C.kxQ<  
~n/ $  
*SO{\bu  
import java.io.*; +t2SzQ j>  
import java.net.*; U?!>Nd  
O 1oxZj <  
V#jWege  
public class FileSplitterFetch extends Thread { F_bF  
apk4 j\i?5  
,<A$h3*  
String sURL; //File URL .6OgO{P:  
long nStartPos; //File Snippet Start Position !d&C>7nb  
long nEndPos; //File Snippet End Position .SWt3|Pi5  
int nThreadID; //Thread's ID 2y%,p{="  
boolean bDownOver = false; //Downing is over mYc.x  
boolean bStop = false; //Stop identical #Oha(mRY  
FileAccessI fileAccessI = null; //File Access interface )z8!f}:De=  
%0Y=WYUH>  
KLX/O1B  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,TRTRb;  
{ $#|gLVOQ  
this.sURL = sURL; <94_@3  
this.nStartPos = nStart; (5Sivw*mP  
this.nEndPos = nEnd; IG3,XW  
nThreadID = id; $x6$*K(F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Iyo@r%I  
} H'qG/@u-l  
=YG _z^'  
` gW<M  
public void run() mm5$> [%U  
{ Uje|`<X  
while(nStartPos < nEndPos && !bStop) oy<WUb9W  
{ +I>p !v  
'q * Bdx  
:pRpv hm  
try{ sK=0Np=`  
URL url = new URL(sURL); .ZMW>U>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  KQ[!o!%  
httpConnection.setRequestProperty("User-Agent","NetFox"); =H<0o?8?c  
String sProperty = "bytes="+nStartPos+"-"; JCY~W=;v  
httpConnection.setRequestProperty("RANGE",sProperty);  8L*GE  
Utility.log(sProperty); 8J)xzp`*)  
kcDyuM`  
FWC5&tM  
InputStream input = httpConnection.getInputStream(); P_u|-~|\  
//logResponseHead(httpConnection); f+.T^es  
 d^(1TNS  
CB~Q%QLG  
byte[] b = new byte[1024]; M.td^l0  
int nRead; S^Au#1e   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H[b}kZW:a  
{ U}$DhA"r"  
nStartPos += fileAccessI.write(b,0,nRead); 4'p=p#o  
//if(nThreadID == 1) )f dE6  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VGqa)ri"  
} irk*~k ?  
p*5\+WO>!(  
I\ | N  
Utility.log("Thread " + nThreadID + " is over!"); D=TL>T.b f  
bDownOver = true; j6(?D*x  
//nPos = fileAccessI.write (b,0,nRead); ,i.%nZw\  
} xug)aE  
catch(Exception e){e.printStackTrace ();} iRi{$.pVJ  
} h3gWOU  
} IHC1G1KW=A  
:D7|%KK  
?GBkqQ  
//打印回应的头信息 Z2"? &pKV  
public void logResponseHead(HttpURLConnection con) hO[3Z ^X  
{ US{3pkr;I]  
for(int i=1;;i++) +%\oO/4Fs  
{ 8j1ekv  
String header=con.getHeaderFieldKey(i); UhmTr[&  
if(header!=null) gK|R =J  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O--7<Q\  
Utility.log(header+" : "+con.getHeaderField(header)); IaFr&  
else ;W:6{9m ze  
break; oVCmI"'  
} I?Q+9Rmm`J  
} _7a'r</@  
Q:6VYONN  
ESb ]}c:  
public void splitterStop() yg]2erR  
{ zdSh:  
bStop = true; 0iEa[G3  
} 0@Kkl$O>mb  
@/%{15s.  
<5@PWrU?[[  
} `P@- %T  
~2 u\  
buk=p-oi  
/* l2hG$idC  
**FileAccess.java wcDjg&:=ml  
*//文件访问(定位,写) s~26  
package NetFox; +CM7C%U   
import java.io.*; f=J<*h  
2>em0{e  
bl/,*Wx:4.  
public class FileAccessI implements Serializable{ ^%y`u1ab  
{F|48P;J  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .I$}KE)  
RandomAccessFile oSavedFile; si(;y](  
long nPos; uHNpfKnZ  
A\te*G0:S  
8cHE[I  
public FileAccessI() throws IOException xn}BB}s{t  
{ *@ED}Mj+  
this("",0); GbU@BN+_  
} ^+?|Qfi  
)y7_qxwbV  
pJ, @Y>  
public FileAccessI(String sName,long nPos) throws IOException ED} 31L  
{ K X]oE+:  
oSavedFile = new RandomAccessFile(sName,"rw"); i[semo\E  
this.nPos = nPos; V:bV ?lt  
oSavedFile.seek(nPos); |Y_ -  
} `0#H]=$2h  
}1+%_|Y-E  
b4,jN~ci  
public synchronized int write(byte[] b,int nStart,int nLen) K'6[J"dB  
{ ,ZI\dtl  
int n = -1; IPA*-I57  
try{ +yt6(7V*  
oSavedFile.write(b,nStart,nLen); ;_<)JqUh  
n = nLen; JhR W[~  
} ^&c$[~W  
catch(IOException e) hv)7H)|l~]  
{ Sav`%0q?7a  
e.printStackTrace (); 8 |h9sn;P  
} N b3$4(F  
& 7QH^  
8V4V3^_xs  
return n; igDyp0t  
} A~-#@Z  
B94 &elu  
dGgP_ S  
} M:ai<TZ]  
m$y]Lf  
p {%t q$}.  
/* rPq<Xb\  
**SiteInfoBean.java #w3ru6*W  
*/ VTe.M[:  
package NetFox; S-E++f9D~  
6 o[/F3`  
,&a`d}g&G  
public class SiteInfoBean { "2HY5 AE  
4?]oV%aP)  
p4/$EPt)lY  
private String sSiteURL; //Site's URL Ae|P"^kZ  
private String sFilePath; //Saved File's Path ,J9}.}Hd  
private String sFileName; //Saved File's Name 'UDBV  
private int nSplitter; //Count of Splited Downloading File r25Z`X Z  
Nh)[r x  
ekzjF\!y  
public SiteInfoBean() Go+[uY^  
{//nSplitter的缺省值为5 }_46y*o8  
//default value of nSplitter is 5 I 8Y*@$h  
this("","","",5); F>Y9o- o2  
} /B HepD}  
Di??Q_$ak  
f?0s &Xo  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k7bl'zic  
{ lg/sMF>z\f  
sSiteURL= sURL; q=Xg*PM,  
sFilePath = sPath; A1JzW)B  
sFileName = sName; 8@7AE"  
this.nSplitter = nSpiltter; q9}2  
shi Hy*(v  
dl/X."iv!  
} 2Ug.:![  
kG3!(?:  
r#~K[qb  
public String getSSiteURL() dm^H5D/A  
{ U'3Fou}  
return sSiteURL; +0#JnqH"  
} Hql5oA  
`facFt[\  
{fG|_+tl3o  
public void setSSiteURL(String value) WV_`1hZX  
{ 52<~K  
sSiteURL = value; {^&k!H2  
} ;mJkqbVol  
8gpBz'/,  
Tt6{WDscZ  
public String getSFilePath() zHx mA  
{ 9A;6x$s  
return sFilePath; wA0eG@xi)  
} o8D{dS>,PL  
vw r RZ"2  
@6%gIsj<H  
public void setSFilePath(String value) w#{l 4{X|  
{ }GRMZh_8  
sFilePath = value; h;n\*[fDc  
} jyjQzt >\  
^('cbl  
G `Izf1B`I  
public String getSFileName() |9]PtgQv7  
{ ?N#[<kd  
return sFileName; 6:RMU  
} g3a/;wl  
.;%q/hP  
/oDpgOn  
public void setSFileName(String value) 9qeZb%r&  
{ "8t\MKt(  
sFileName = value; J8h7e}n?  
} B "n`|;r5  
rU*q@y Px  
9UmBm#"  
public int getNSplitter() Y2vj}9jK  
{ zv9M HC &  
return nSplitter; #J~Xv:LgD  
} =5_y<0`4  
=L16hDk o  
xvO 3BU~2  
public void setNSplitter(int nCount) _> Ln@  
{ {jG.=}/Dk  
nSplitter = nCount; AgI>  
} ZV#$Z  
} 4@~a<P#  
qp1\I$Y  
4f jC  
/* :tlE`BIp  
**Utility.java @{bb'q['@  
*/ 5h(jeT8"  
package NetFox; u7(];  
=f4< ({9  
x.G"D(  
public class Utility { u !.DnKu  
ULTNhq R*n  
#'g^Za  
public Utility() \AJS,QD  
{ {0fz9"|U  
=?+w)(*0c  
wzxdVn 'S  
} E4i@|jE~)  
`+fk`5Y  
//线程睡眠 p Dm K  
public static void sleep(int nSecond) l<n5gfJ  
{ 1 Xa+%n9  
try{ wVQdUtmk  
Thread.sleep(nSecond); ,$PFI(Whk  
} $Br>KJ%'g  
catch(Exception e) pzAoq)gg:  
{ !(yT7#?hP  
e.printStackTrace (); uwId  
} rx}*u3x=  
} F1\`l{B,\  
5Fr;  
//日志 3~:0?Zuq  
public static void log(String sMsg) dWjx"7^  
{ e|~C?Ow'J  
System.err.println(sMsg); QK'`=MU  
} "]w!`^'_  
+>u>`|  
h$|3dz N  
public static void log(int sMsg) pIvfmIm  
{ 3)xbnRk  
System.err.println(sMsg); hXPocP  
} #_{0Ndp2  
} tw-fAMwU  
yT&x`3f"i  
n{L:MT9TD  
/* lD-V9   
**TestMethod.java  2aFT<T0  
*/ ] ZDTn  
package NetFox; #>" }q3RO  
2Gm-\o&Td"  
fqN75['n  
public class TestMethod { "I@v&(Am;  
CJm.K  
prwC>LE  
public TestMethod() P3i^S_  
{ ///xx/weblogic60b2_win.exe "* +\KPCU  
try{ 8,_ -0_^$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _HLC>pH~#  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 487YaioB$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g;l'VA3v  
fileFetch.start(); "bPCOJ[v9  
} XzW7eO ,A  
catch(Exception e){e.printStackTrace ();} .uBO  
rAM *\=  
u]P03B  
} ) b/n)%6  
ENO? ;  
b~jIv:9T  
public static void main(String[] args) epn#qeX  
{ !O 4<I_EY{  
new TestMethod(); >dyhox2*"  
} eN2dy-0  
} G l_\Vy  
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