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http断点续传简单实现(java)

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/* ~6:LUM  
**SiteFileFetch.java pl#o!j(i  
*/ L`\`NNQC  
package NetFox; *mQDS.'AB@  
import java.io.*; Wl !!5\  
import java.net.*; QFNz9c  
^?6 W<  
{rb-DB-/5M  
public class SiteFileFetch extends Thread { q3x;_y^  
Q}Ze-JIL$  
Ie2w0Cs28  
SiteInfoBean siteInfoBean = null; //文件信息Bean .hQ3A"  
long[] nStartPos; //开始位置 CFBUQMl >  
long[] nEndPos; //结束位置 [)H,zpl  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Vgqvvq<S  
long nFileLength; //文件长度 [^U;  
boolean bFirst = true; //是否第一次取文件 xV,4U/ T  
boolean bStop = false; //停止标志 c#n4zdQd]5  
File tmpFile; //文件下载的临时信息 Y*kh$E%<#  
DataOutputStream output; //输出到文件的输出流 qXU:A-IdIl  
Z9"{f)T  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -y l4tW  
public SiteFileFetch(SiteInfoBean bean) throws IOException KO-Zz&2f  
{ miG; ]-"^  
siteInfoBean = bean; -; us12SZ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); P^b:?%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); tIxhSI^  
if(tmpFile.exists ()) ~"JE![XR  
{ npO@Haw  
bFirst = false; i9&K  
read_nPos(); Ho)t=qn  
} &N/|(<CB  
else ~ ^rey  
{ dThn?  
nStartPos = new long[bean.getNSplitter()]; d^Zo35X  
nEndPos = new long[bean.getNSplitter()]; u+mjguIv  
} Q$?7)yyu+  
*#Lsjk~_-  
G>=9gSLM  
V4`:Vci Aw  
} iJ`%yg,  
qXrt0s[  
I 9{40_  
public void run() A;fB6  
{ ;!l*7}5X=  
//获得文件长度 #gX%X~w$F  
//分割文件 vz;7} Zj]  
//实例FileSplitterFetch A*\o c  
//启动FileSplitterFetch线程 tA! M  
//等待子线程返回 IS,zy+w  
try{ DnNt@e2|  
if(bFirst) Hi; K"H]x1  
{ ]k'#g Z$  
nFileLength = getFileSize(); #MhNdH#  
if(nFileLength == -1) lBlSNDs  
{ |t4Gz1"q=8  
System.err.println("File Length is not known!"); 2 ?Pt Z  
} _l24Ba$F6  
else if(nFileLength == -2) }g>dn  
{ c y=I0  
System.err.println("File is not access!"); bU;}!iVc]  
} .)i O Du  
else +=ZWau   
{ CN\|_y  
for(int i=0;i<nStartPos.length;i++) hsTFAfa'  
{ }mKGuCoH>  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l-<3{!  
} 22)0zY%\  
for(int i=0;i<nEndPos.length-1;i++) !Qv5"_  
{ J6)efX)j-p  
nEndPos = nStartPos[i+1]; 8%;}LK  
} <Jwi ~I=^  
nEndPos[nEndPos.length-1] = nFileLength; J 6(~>g  
} &K5C=]4  
} Y%78>-2 L  
DC?21[60  
V*6l6-y~Ih  
//启动子线程 l;XU#6{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gHQPhe#n  
for(int i=0;i<nStartPos.length;i++) .abyYVrN4?  
{ /hm84La  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dV5PhP>6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Tg"' pO  
nStartPos,nEndPos,i); ZhhI@_sz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >EBZ$X  
fileSplitterFetch.start(); WW//heJe-  
} x`]Of r'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +<pVf%u5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nGq]$h  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B3y?.  
nEndPos = " + nFileLength); %*$5!;  
// fileSplitterFetch[nPos.length-1].start(); Wyy^gJl  
k0H?9Z4k5  
NFB *1_m  
//等待子线程结束 6N9 c<JC  
//int count = 0; ]YCPyc:  
//是否结束while循环 W*YxBn4  
boolean breakWhile = false; O!:QJ ^8 d  
-h>Z,-DE6  
r0)JUc}Fyq  
while(!bStop) ! G*&4V3Mg  
{ f=t:[ < )  
write_nPos(); c*N50%=4  
Utility.sleep(500); Iq)(UfaSve  
breakWhile = true; @)o0GHNP  
xLA~1ZSVJw  
} sf YCz  
for(int i=0;i<nStartPos.length;i++) )HEfU31IC  
{ WHp97S'd  
if(!fileSplitterFetch.bDownOver) MQwIPjk8  
{ IZO@V1-m  
breakWhile = false; D,c!#(v cK  
break; 25aNC;J  
} 6X dWm  
} bRWIDPh  
if(breakWhile) t(}/g  
break; FXS^^p P  
cb +l"FI7  
uCw>}3  
//count++; RG&I\DTyt  
//if(count>4) Dt W*n1Bt  
// siteStop(); `&7mHa61  
} /r276Q  
-7k[Vg?  
wAw42{M  
System.err.println("文件下载结束!"); 8h@q  
} ;xfO16fNk  
catch(Exception e){e.printStackTrace ();} 3FFaEl  
} 92ZWU2"  
Ffnk1/ Zy  
CK2B  
//获得文件长度 y>$1 UwQ  
public long getFileSize() B1E$v(P3M  
{ '0Lov]L  
int nFileLength = -1; BYS lKTh  
try{ P^"R4T  
URL url = new URL(siteInfoBean.getSSiteURL()); L~IE,4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H#+\nT2m  
httpConnection.setRequestProperty("User-Agent","NetFox"); jk )Vb  
q%>7L<r  
@|BD|{k  
int responseCode=httpConnection.getResponseCode(); GMz8B-vk  
if(responseCode>=400) eI^gV'UK  
{ 0mTEim  
processErrorCode(responseCode); jO=*:{#x  
return -2; //-2 represent access is error wtSvJI~o)  
} Dv@ PAnk3C  
s2^B(wP  
k=?^){[We  
String sHeader; Jn=42Q:>  
mwIk^Sz]@  
8"x9#kyU<3  
for(int i=1;;i++) (_K_`5d;QI  
{ )Ob]T{GY  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X'f)7RbT  
//Utility.log(in.readLine()); \b$<J.3  
sHeader=httpConnection.getHeaderFieldKey(i); \ZMP_UU(  
if(sHeader!=null) Z ] '>  
{ r?pZ72 q  
if(sHeader.equals("Content-Length")) s O=4IBE  
{ HMV)U{  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4@6 <  
break; W .U+.hR  
} T^]7R4 Fg  
} l xe`u}[  
else 3htq[Ren  
break; m2(E>raV6  
} T6uMFD4 |  
} !{(ls<  
catch(IOException e){e.printStackTrace ();} pA.._8(t  
catch(Exception e){e.printStackTrace ();} qp>N^)>  
4d`+CD C  
7Lg7ei2mN7  
Utility.log(nFileLength); } Gr&w-v  
n?:2.S.8  
]v\^&7pW  
return nFileLength; ;'}'5nO=$  
} &cc9}V)M  
mw4JQ\  
)t%h[0{{  
//保存下载信息(文件指针位置) RDJ+QOVKg  
private void write_nPos() eLV.qLBUs  
{ #dxvz^2V.3  
try{ s]Gd-j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .*Vkua  
output.writeInt(nStartPos.length); j0x5@1`6G  
for(int i=0;i<nStartPos.length;i++) ZVL gK}s  
{ > aG=T{  
// output.writeLong(nPos); WL U}  
output.writeLong(fileSplitterFetch.nStartPos); PO o%^'(  
output.writeLong(fileSplitterFetch.nEndPos); < bFy(+  
} 2 n)gpLIJ  
output.close(); d)tiO2W  
} Qdu$Os  
catch(IOException e){e.printStackTrace ();} |9IC/C!HC  
catch(Exception e){e.printStackTrace ();} 1k[GuG%/K  
} 6{=_718l`  
mj2Pk,,SA  
jO8X:j09A  
//读取保存的下载信息(文件指针位置) 8KMv Ac  
private void read_nPos() Uw)=WImz[  
{ CxDcY  
try{ 6+3$:?  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jj,r <T  
int nCount = input.readInt(); l5k?De_(x  
nStartPos = new long[nCount]; {<K=*r rZ  
nEndPos = new long[nCount]; 9x?'}  
for(int i=0;i<nStartPos.length;i++) #{*LvI&  
{ =7 w>wW-  
nStartPos = input.readLong(); ZzcPiTSO  
nEndPos = input.readLong(); V_"f|[1  
} !D:Jbt@R<n  
input.close(); dZ]Rqr _!  
} %dW%o{  
catch(IOException e){e.printStackTrace ();} ,mKObMu  
catch(Exception e){e.printStackTrace ();} "3}<8 c  
} B!;+_%P76  
-V5w]F'  
/t5p-  
private void processErrorCode(int nErrorCode) ]Blf9h7  
{ 4h8*mMghs  
System.err.println("Error Code : " + nErrorCode); bL`eiol6  
} 2*2:-o cl$  
z%sy$^v@vD  
%e? fH.)  
//停止文件下载 M0w/wt|  
public void siteStop() }mk>!B}=  
{ y=Q!-~5|fF  
bStop = true; O/b+CSS1  
for(int i=0;i<nStartPos.length;i++) C:i|-te  
fileSplitterFetch.splitterStop(); @i LIU}+  
"=A>}q@;H  
rs]I  
} Lm6**v  
} u =J&~  
//负责部分文件的抓取 h@1!T  
**FileSplitterFetch.java ss iokLE  
*/ 6 BAW  
package NetFox; pC(sS0J  
;ME)Og  
~OypE4./1  
import java.io.*; >jTp6tu,  
import java.net.*; *Y6xvib9*  
I7(?;MpI  
nidr\oFUIn  
public class FileSplitterFetch extends Thread { 0* F}o)n/m  
8P2 J2IU  
)Gk`[*q ;  
String sURL; //File URL O!&,5Dy  
long nStartPos; //File Snippet Start Position F9flSeN  
long nEndPos; //File Snippet End Position wtH~-xSB|  
int nThreadID; //Thread's ID fU+Pn@'  
boolean bDownOver = false; //Downing is over uQ/h'v  
boolean bStop = false; //Stop identical l]6% lud8_  
FileAccessI fileAccessI = null; //File Access interface Q(Gl{#b  
nwmW.(R4  
1m@^E:w  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9 OT,TpA  
{ N#ioJ^}n:  
this.sURL = sURL; eQDX:b  
this.nStartPos = nStart; 3EK9,:<Cf  
this.nEndPos = nEnd;  L,LNv  
nThreadID = id; M;.ZM<Ga  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )rtomp:X  
} o:p *_>&  
1G^#q,%X_v  
GJA`l8`SQ  
public void run() ae+*=,  
{ yj_4gxJ\  
while(nStartPos < nEndPos && !bStop) o{WyQ&2N  
{ n<7q`tM#  
ej(ikj~j  
<AoXEu D  
try{ >m6&bfy\q  
URL url = new URL(sURL); 'T8W!&$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  Mps5Vv  
httpConnection.setRequestProperty("User-Agent","NetFox"); =^;P#kX  
String sProperty = "bytes="+nStartPos+"-"; 5h{`<W  
httpConnection.setRequestProperty("RANGE",sProperty); +-$Ko fnM  
Utility.log(sProperty); 7h9U{4r: M  
19UN*g3(  
u bW]-U=T  
InputStream input = httpConnection.getInputStream(); xTz%nx  
//logResponseHead(httpConnection); W!L+(!&H  
g(4bBa9y  
n/4i|-^  
byte[] b = new byte[1024]; r 2:2,5_  
int nRead; /)3Lnn{W  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  aSutM  
{ 0<p{BL 8  
nStartPos += fileAccessI.write(b,0,nRead); S<wj*"|.s  
//if(nThreadID == 1) PoSpkJH  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a;AzY'R  
} >QkP7Kb  
8V/L:h#7  
~+6Vdx m  
Utility.log("Thread " + nThreadID + " is over!"); L=; -x9  
bDownOver = true; ??&<k   
//nPos = fileAccessI.write (b,0,nRead); vX|UgK?2^  
} *m+BuGt|  
catch(Exception e){e.printStackTrace ();} }T_Te?<&  
} p9eRZVy/  
} ca<"  
G&f8n  
4Y\wnwI  
//打印回应的头信息 <n"C,  
public void logResponseHead(HttpURLConnection con) Nf41ZT~  
{ ""iaGH+Cxw  
for(int i=1;;i++) 5\fCd|  
{ zg)sd1@  
String header=con.getHeaderFieldKey(i); x2Lq=zwJ  
if(header!=null) &HZmQ>!R D  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RO(TvZ0pE  
Utility.log(header+" : "+con.getHeaderField(header)); D<$XyP  
else /iaf ^ >  
break; l@Z6do  
} ay )/q5  
} #U mF-c  
}iB|sl2J  
 t+uE  
public void splitterStop() (qM j-l  
{ ,M5}4E7L%s  
bStop = true; r=.A'"Kf  
} !^c@shLN4  
dEa<g99[?  
2BXy<BM @  
} ~nLN`H d  
q!~ -(&S  
xGk6n4Gg  
/* V N{NA+I  
**FileAccess.java 1 T<+d5[C  
*//文件访问(定位,写) "_UdBG  
package NetFox; aW_oD[l  
import java.io.*; _*M42<wcO  
9p* gU[  
E>LkJSy=  
public class FileAccessI implements Serializable{ Y*oDO$6  
K6JVg$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CG\tQbum  
RandomAccessFile oSavedFile; "ICC B1N|  
long nPos; -7H^n#]  
h"mi"H^o  
BimjQ;jtI  
public FileAccessI() throws IOException eDI= nSo  
{ e!-,PU9+  
this("",0); W<ZK,kv  
} O)|P,?  
u|#>32kV  
#hfuH=&oh  
public FileAccessI(String sName,long nPos) throws IOException 2zSG&",2D  
{ ] Wy)   
oSavedFile = new RandomAccessFile(sName,"rw"); Psura$:  
this.nPos = nPos; u9woEe?  
oSavedFile.seek(nPos); Jq.lT(E8D  
} O=cxNy-I  
,fDEz9-,  
`^JJ&)4iv  
public synchronized int write(byte[] b,int nStart,int nLen) n"PJ,ao  
{ EI>6Nh  
int n = -1; %=we `&  
try{ Z7rJ}VP  
oSavedFile.write(b,nStart,nLen); Cb t{ H}I3  
n = nLen; ]M>9ULQ  
} N]EcEM#  
catch(IOException e) d6{Gt"  
{ f*{ YFg?*&  
e.printStackTrace (); sxKf&p;  
} ?^mi3VM  
-~[9U,  
/^{BUo  
return n; Jf)bHjC_V  
} JCcZuwu[  
 9fnA  
#o/ H~Iv  
} 5Z/GK2[HL  
hRI"y":zD  
>7`<!YJkK  
/* 'TC/vnM  
**SiteInfoBean.java .MW@;  
*/ &;,,H< p  
package NetFox; 1(Y7mM8\  
93qwH%  
`!:q;i]}  
public class SiteInfoBean { 1% F?B-k  
<$w?/y/'  
7'-Lp@an  
private String sSiteURL; //Site's URL 9j ]sD/L5q  
private String sFilePath; //Saved File's Path HmfG$Z  
private String sFileName; //Saved File's Name X:a`B(@S  
private int nSplitter; //Count of Splited Downloading File a {}|Bf<  
<}U'V}g  
L9Z;:``p  
public SiteInfoBean() _Y=2/*y^  
{//nSplitter的缺省值为5 <^~FLjsfg  
//default value of nSplitter is 5 .?p\n7  
this("","","",5); /&& 2u7*  
} do-ahl,  
etT +  
H.<a`m m8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \;-fi.Hrf$  
{ |6UtW{2I/  
sSiteURL= sURL; [ xOzzp4  
sFilePath = sPath; ;= j@, yu  
sFileName = sName; k:2QuG^  
this.nSplitter = nSpiltter; )#a[-.OI  
<^b7cOFQ  
G2LK]  
} <H1 `  
(Rk_-9_E.  
scuHmY0  
public String getSSiteURL() , P'P^0qJ  
{ Y={&5Mir  
return sSiteURL; RjF'x  
} QIN."&qC^  
v5;I]?72l~  
9Suu-A  
public void setSSiteURL(String value) d_n7k g+  
{  ;N B:e  
sSiteURL = value; -[= drj9I  
} svelYe#9z  
g~7Ri-"  
FJ*i\Q/D  
public String getSFilePath() Ftw;Yz  
{ l$K,#P<)  
return sFilePath; AM"Nn L"  
} )&era ` e[  
Uie?9&3  
O20M[_S  
public void setSFilePath(String value) e{;OSk`x  
{ |9"p|6G?B  
sFilePath = value; 7&`}~$>}>e  
} a9n^WOJ6  
qQpnLV4  
(>mI'!4d  
public String getSFileName() YY?a>j."a  
{ /&u<TJ4  
return sFileName; N=:5eAza  
} 0JgL2ayIVI  
`28};B>  
%}86D[PF  
public void setSFileName(String value) M :3u@06a  
{ B!gGK|8  
sFileName = value; $F.([?)k?  
} ELh8ltLY  
Xi?b]Z  
pE{yv1Yg  
public int getNSplitter() )$w*V9d  
{ "#v=IJy&r  
return nSplitter; vHAg-Av c  
} \BWyk A>  
j1SMeDDM ~  
k5kdCC0FCk  
public void setNSplitter(int nCount) )uv=S;+  
{ _3]][a,  
nSplitter = nCount; {_(\` >  
} DC1'Kyk  
} =0 @&GOq  
kOvDl!^  
 tvXW  
/* 6"c1;P!4   
**Utility.java 'Dvv?>=&  
*/ mh<=[J,%p  
package NetFox; :Rs^0F8)c  
"MIq.@8ra  
c}3W:}lW  
public class Utility { t}v2$<!I  
b{fQ|QD{^E  
@fu M)B1"  
public Utility() X7,PEA  
{ Q'k\8'x  
"x@='>:$  
p8s:g~ W  
} |uW:r17  
L< zD<M  
//线程睡眠 +A~\tK{  
public static void sleep(int nSecond) tO_H!kP  
{ +(uYwdcN  
try{ F}"]92  
Thread.sleep(nSecond); LqdY Qd51  
} LZ@|9!KDw  
catch(Exception e) &z"krM]G  
{ j CTAKaq  
e.printStackTrace (); }F+zs*S  
} Qu,8t 8  
} d:G]1k;z  
P}.7Mehf  
//日志 AxxJk"v'y  
public static void log(String sMsg) m/NdJMoN=  
{ 3] 1-M  
System.err.println(sMsg); OB ~X/  
} "O8gJ0e  
IV lf=k  
) 'j:  
public static void log(int sMsg) +UJuB  
{ _C\[DR0n  
System.err.println(sMsg); 1FtM>&%4  
} uxg9yp@|  
} v(OBXa9  
\c[IbL07  
{cpEaOyOM  
/* aA-  
**TestMethod.java PSawMPw  
*/ tNVV)C  
package NetFox; %gnM( pxl  
[i0Hm)Bd3  
k%y9aO  
public class TestMethod { T0)"1D<l  
_Lw OOZj  
`nUO l  
public TestMethod() l"n{.aL  
{ ///xx/weblogic60b2_win.exe >;z<j$;F<  
try{ iCP/P%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CE15pNss  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +i\&6HGK;-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Sx    
fileFetch.start(); #d{=\$=  
} Kb =@ =Xta  
catch(Exception e){e.printStackTrace ();} Z ,^9 Z  
^I KO2Ft  
]nhr+;of/-  
} b;|55Y  
KYJjwXT28W  
~) ?  
public static void main(String[] args) lyCW=nc  
{ y/V%&.$o=  
new TestMethod(); GRy-+#,b"  
} *&AfR8x_z  
} {{C`mgC  
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