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http断点续传简单实现(java)

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/* ffqz :6  
**SiteFileFetch.java XF 8$D  
*/ pv #uLo  
package NetFox; KM ;'MlO  
import java.io.*; @,{', =L6  
import java.net.*; m?Qr)F_M  
&E&e5(&$  
{(,[  
public class SiteFileFetch extends Thread { b 5X~^L  
dJ}E,rW}  
'Bv)UfZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean }- P ='AyL  
long[] nStartPos; //开始位置 Mk~]0d  
long[] nEndPos; //结束位置 1EvK\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 b;XUv4~V  
long nFileLength; //文件长度 LCMCpEtY*K  
boolean bFirst = true; //是否第一次取文件 qvH7otA  
boolean bStop = false; //停止标志 #A '|O\RGP  
File tmpFile; //文件下载的临时信息 u79,+H@ep  
DataOutputStream output; //输出到文件的输出流 8NRc+@f|m  
]c'12 g]h  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) P:gN"f6  
public SiteFileFetch(SiteInfoBean bean) throws IOException vS{zLXg  
{ 8I`t`C/4  
siteInfoBean = bean; b=Y:`&o=[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); NY`$D}Bi  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); s;'j n_,0  
if(tmpFile.exists ()) DcQ[zdEz+  
{ 2HemPth  
bFirst = false; ] 3@.)  
read_nPos(); W+C@(}pt  
} (!@ Q\P  
else (79y!&9p  
{ v0yaFP#kG  
nStartPos = new long[bean.getNSplitter()]; A1A/OU<Vb  
nEndPos = new long[bean.getNSplitter()]; CAhkv0?8  
} 3. kP,  
IP]"D"  
[8o!X)  
5D32d1A  
} ^K#PcPF-j  
.%pbKi `  
_ xAL0 (  
public void run() U?}>A5H  
{ < c}cgD4  
//获得文件长度 f;u<r?>Z  
//分割文件 mrzrQ@sN  
//实例FileSplitterFetch I-QaR  
//启动FileSplitterFetch线程 wK_I"  
//等待子线程返回 JIl<4 %A  
try{ Uo!#p'<w)p  
if(bFirst) $cxulcay=  
{ wap@q6fz<  
nFileLength = getFileSize(); &3Q!'pJJ  
if(nFileLength == -1) K9#=@}!3L  
{ 5f:Mb|. ?  
System.err.println("File Length is not known!"); T w!]N%E  
} wIv_Z^% V  
else if(nFileLength == -2) 8e`'Ox_5a  
{ Y 7a<3>  
System.err.println("File is not access!"); l 4zl|6%  
} J5Nz<  
else x>?jfN,e  
{ b#:Pl`n6u  
for(int i=0;i<nStartPos.length;i++) =Mb1)^m  
{ XQW+6LEQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]pZxbs&Vb  
} D{]t50a.  
for(int i=0;i<nEndPos.length-1;i++) Fo=hL  
{ _k0 X)N+li  
nEndPos = nStartPos[i+1]; \B0,?_i  
} (o!v,=# 6{  
nEndPos[nEndPos.length-1] = nFileLength; ]"jJgO^  
} 7>Af"1$g  
} 7gLN7_2  
#bqc}h9  
_Ra$"j  
//启动子线程 BM(8+Wj  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;^9Ao>(?y  
for(int i=0;i<nStartPos.length;i++) d+1q[,-  
{ _&Hq`KJm  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I.[2-~yf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vPm&0,R*y:  
nStartPos,nEndPos,i); 5Av bKT  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Ts6M,Fpp  
fileSplitterFetch.start(); ? 1OZEzA!  
} ]wH,534  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F__j]}?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x<m{B@3T  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gEVN;G'B<=  
nEndPos = " + nFileLength); N3D{t\hg  
// fileSplitterFetch[nPos.length-1].start(); Sn I-dXNF  
MeXzWLH  
He#5d!cf:M  
//等待子线程结束 _vQtV]  
//int count = 0; *} pl  
//是否结束while循环 j-e gsKR  
boolean breakWhile = false; i8F^ N=  
VJK?"mX  
u&q RK>wLa  
while(!bStop) aZ[ aZU  
{ N$8do?  
write_nPos(); 0b )^#+  
Utility.sleep(500); DrfOz#a0Uu  
breakWhile = true; O]"3o,/]G  
ea"!:cL(g  
}:5_vH0  
for(int i=0;i<nStartPos.length;i++) OLThi[Yn  
{ G~SgI>Q  
if(!fileSplitterFetch.bDownOver) 6}Se$XMl  
{ O~E6"v Q  
breakWhile = false; 83 O+`f  
break; (=hXt=hZ  
} 4eZ  
} BoJYP  
if(breakWhile) aR3R,6ec  
break; I9sx*'  
zG\g{cB  
Q_ zGs6  
//count++; p$>e{-u  
//if(count>4) >EVlMt27'  
// siteStop(); j"FX ?|4  
} q|*}>=NX  
OQ[E-%v1 R  
]}4{|& e  
System.err.println("文件下载结束!"); h5+qP"n!?q  
} aNZJs<3;'D  
catch(Exception e){e.printStackTrace ();} t`PA85.|d  
} m!{}Y]FZn  
W<J".2D  
'dE G\?v9  
//获得文件长度 ^%)H;  
public long getFileSize() 1b4aY> Z  
{ +-b:XeHSZ  
int nFileLength = -1; <SiD m-=E  
try{ (~YFm"S  
URL url = new URL(siteInfoBean.getSSiteURL()); 1!u}~E_   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TTg>g~t`  
httpConnection.setRequestProperty("User-Agent","NetFox"); -7 GF2 @  
.C]V==z`[4  
]SNA2?q  
int responseCode=httpConnection.getResponseCode(); 9fk@C/$  
if(responseCode>=400) VieX 5  
{ q#fj?`k  
processErrorCode(responseCode); \ (y6o}aW  
return -2; //-2 represent access is error v3b[08 F  
} m$T?~o o  
l2v4SvbX  
B7:8%r/  
String sHeader; rlj @ '  
=@#[@Ia  
UQGOCP_  
for(int i=1;;i++) yo)a_rY  
{ ~vD7BO`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 19 h7 M  
//Utility.log(in.readLine()); X#l]%IrW!  
sHeader=httpConnection.getHeaderFieldKey(i); Z]$RO  
if(sHeader!=null) # 2As-9  
{ .C avb  
if(sHeader.equals("Content-Length")) ;^5d^-T  
{ ISHNeO8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C$X )I~M  
break; (p1y/"Xh  
} w7b?ve3-  
} W"9?D  
else Evd>s  
break; wGd4:W  
} OrX x0Hn  
} P;%4Imq3  
catch(IOException e){e.printStackTrace ();} :e-&,K  
catch(Exception e){e.printStackTrace ();} .@0i,7S  
:t &ib}v  
s : c  
Utility.log(nFileLength); U#oe8(?#  
#q{i<E 07  
P8DT2|Z6f]  
return nFileLength; 2ql7*g?Uq@  
} jEQr{X7bEL  
z/bJDSQ  
SB#YV   
//保存下载信息(文件指针位置) #J AU5d  
private void write_nPos() 28l",j)S  
{ '}a[9v76  
try{ ?!H <V@a  
output = new DataOutputStream(new FileOutputStream(tmpFile)); S>~QuCMY  
output.writeInt(nStartPos.length); ZyE2=w7n  
for(int i=0;i<nStartPos.length;i++) "hRw_<  
{ zx7*Bnu0  
// output.writeLong(nPos); M[5zn  
output.writeLong(fileSplitterFetch.nStartPos); vF, !8e'v  
output.writeLong(fileSplitterFetch.nEndPos); o'.6gZ gk  
} Ro+/=*ql~  
output.close(); vt`hY4  
} uHdrHP  
catch(IOException e){e.printStackTrace ();} E.v~<[g  
catch(Exception e){e.printStackTrace ();} &wj;:f  
} `Q!|/B  
~__]E53F  
Ya] qo]  
//读取保存的下载信息(文件指针位置) "rz|sbj  
private void read_nPos() #84pRU~  
{ Q2;zve&Dl  
try{ \XR%pC  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [V`j@dV  
int nCount = input.readInt(); pyK|zvr-r  
nStartPos = new long[nCount]; 9WQC\/w  
nEndPos = new long[nCount]; +O23@G?x  
for(int i=0;i<nStartPos.length;i++) }?B=R#5  
{ xw-x<7  
nStartPos = input.readLong(); LP bZ.  
nEndPos = input.readLong(); ocwRU0+j  
} -d\O{{%>.z  
input.close(); <Vp7G%"'W  
} gO-C[j/  
catch(IOException e){e.printStackTrace ();} Yo:l@(  
catch(Exception e){e.printStackTrace ();} .?b2Bd!MC  
} =LJc8@<:f  
gH- e0134%  
>'eOzMBn  
private void processErrorCode(int nErrorCode) | ]`gps  
{ qPdNI1 |  
System.err.println("Error Code : " + nErrorCode); lp5`Kw\  
} $NP5Z0v7  
s)%RmsdL  
' >[KVvm  
//停止文件下载 {Q8DPkW  
public void siteStop() KU[eY}   
{ |i-Qfpn  
bStop = true; ,-Fhb~u  
for(int i=0;i<nStartPos.length;i++) h+|3\>/@9{  
fileSplitterFetch.splitterStop(); -bSe=09;S|  
e47JLW&b  
MP,l*wVd  
} GqhnE>  
} yG58?5\9  
//负责部分文件的抓取 cA ;'~[  
**FileSplitterFetch.java U:>'^tkp  
*/ j[YzBXd V  
package NetFox; }gL9G  
"Iu[)O%  
H n+1I  
import java.io.*; ws5x53K  
import java.net.*; J=6 7As  
CtVY;eG  
cH6ie?KvAo  
public class FileSplitterFetch extends Thread { vBsd.2t~  
w3:WvA5jt  
BR\% aU$u  
String sURL; //File URL &|P@$O>  
long nStartPos; //File Snippet Start Position wJh|$Vn  
long nEndPos; //File Snippet End Position hb9X<N+p  
int nThreadID; //Thread's ID %a+X\\v2  
boolean bDownOver = false; //Downing is over a8aEZ724  
boolean bStop = false; //Stop identical vTjgW?9  
FileAccessI fileAccessI = null; //File Access interface 5bFE;Y;  
49}yw3-  
OlhfBu)~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WZ5[tZf  
{ ~\/>b}^uf'  
this.sURL = sURL; ?RvXO'ml  
this.nStartPos = nStart; >]Hz-2b  
this.nEndPos = nEnd; ]CH@ T9d5V  
nThreadID = id; {rGq|Bj  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ken|!rL  
} T^N Y|Y/  
d9|dHJf  
qAm$yfYs`  
public void run() &'Qz  
{ c&)H   
while(nStartPos < nEndPos && !bStop) uOc>~ITPS  
{ ]4\^>  
:gY$/1SYD  
*wP8)yv7  
try{ dra'1E  
URL url = new URL(sURL); GmtMA|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :ORCsl6-  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^G= wRtS  
String sProperty = "bytes="+nStartPos+"-"; 'T7JXV5  
httpConnection.setRequestProperty("RANGE",sProperty); Gk,{{:M:5  
Utility.log(sProperty); v83uGEq(  
WM: ~P$%cx  
$/],QD_;"  
InputStream input = httpConnection.getInputStream(); p+;Re2Uyg  
//logResponseHead(httpConnection); 1O45M/5\o  
\8Mkb]QA  
>OE.6)'Rm  
byte[] b = new byte[1024]; x +|Fw d  
int nRead; SDiZOypS  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _baqN!N  
{ |`s}PcV  
nStartPos += fileAccessI.write(b,0,nRead); mW1Sd#0  
//if(nThreadID == 1) Ol9U^  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FFbMG:>:  
} q?8MKf[N  
v6oPAqj,r  
<,Sy:>:"  
Utility.log("Thread " + nThreadID + " is over!"); @S?.`o  
bDownOver = true; Q6,rY(b6  
//nPos = fileAccessI.write (b,0,nRead); ixBM>mRK  
} OnH>g"  
catch(Exception e){e.printStackTrace ();} m<8j' [+  
} seHwn'Jn  
} kR^7Z7+#*  
7;;W{W%  
k(=\& T  
//打印回应的头信息 tA#X@HIE  
public void logResponseHead(HttpURLConnection con) H24g+<Tv  
{ =G}_PRn  
for(int i=1;;i++) =t@m:  
{ u>& \@?(  
String header=con.getHeaderFieldKey(i); [2 2IF  
if(header!=null) 2-llT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (m)%5*:  
Utility.log(header+" : "+con.getHeaderField(header)); eN/s W!:P|  
else WES#ZYtT  
break; :1aL ?  
} Xe1P- 6 0  
} #&Is GyU  
?IhB-fd>@  
p*qPcuAA  
public void splitterStop() b{cU<;G)y.  
{ *l+Cl%e  
bStop = true; 6|;Uq'  
} Q!'qC*Gyfn  
kfrY1  
^v ni&sJ  
} m&Yi!7@(  
"@ E3MTW  
}iiHr|l3  
/* #@f[bP}a  
**FileAccess.java ,/2LY4` 5  
*//文件访问(定位,写) lK(Fg  
package NetFox; 1{PG>W  
import java.io.*; "v]%3i.* -  
R.RSQk7;  
$:bih4 @>  
public class FileAccessI implements Serializable{ \~DM   
Le#spvV3J|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FfFak@H  
RandomAccessFile oSavedFile; :0~QRc-u  
long nPos; `DW2spd  
k$7Z^~?Fz  
lP _db&  
public FileAccessI() throws IOException e@]-D FG  
{ 2xxB\J  
this("",0); TkRP3_b  
} S\ ,mR4:  
zF&=U`v  
v}(6 <wnnS  
public FileAccessI(String sName,long nPos) throws IOException ?vtX"Fdz  
{ NC"yDWnO'  
oSavedFile = new RandomAccessFile(sName,"rw"); i!H!;z#  
this.nPos = nPos; OSDy'@   
oSavedFile.seek(nPos); 6(V /yn ~  
} > s EjR!  
-j2 (R?a  
`dkV_ O0  
public synchronized int write(byte[] b,int nStart,int nLen) #bnb ': f  
{ EtJ8^[u2J  
int n = -1; E5GJi  
try{ `N8 7 h"  
oSavedFile.write(b,nStart,nLen); g.DLfwI|  
n = nLen; 't (O$  
} l]Lx L  
catch(IOException e) P,xwSvO#M  
{ CXaWgxlK:a  
e.printStackTrace (); JMa3btLy(  
} C"pB"^0  
</~ 6f(mg  
+Ic ~ f1zh  
return n; J./d!an  
} ocRdbmS  
\Ad7 Gi~  
=t0tK}Y+4  
} y-aRXF=W  
%5'6Tj  
<^R{U&Z@  
/* %j,iAUE<  
**SiteInfoBean.java J5p8nmb  
*/ Wr~yK? : ]  
package NetFox; Ub$n |xn  
#?O &  
cu9Qwm  
public class SiteInfoBean { M4f;/`w  
|i %2%V#  
Sb&lhgW]c  
private String sSiteURL; //Site's URL @4+#Xd7"  
private String sFilePath; //Saved File's Path tNaL;0#Tx  
private String sFileName; //Saved File's Name @r7:NU}  
private int nSplitter; //Count of Splited Downloading File epD?K  
wTq{sW&  
}^ FulsC  
public SiteInfoBean() PD[z#T!'  
{//nSplitter的缺省值为5 R[[ ,q:4  
//default value of nSplitter is 5 C"uahP[Y  
this("","","",5); Sr Ca3PA  
} 0"WDH)7hJ  
wFS2P+e;X  
Tenf:Hm/k  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $9!D\N,}]C  
{ c WAtju?L;  
sSiteURL= sURL; "9y( }  
sFilePath = sPath; f>9s!Hpu_  
sFileName = sName; -#:zsu  
this.nSplitter = nSpiltter; ^c}J,tZ]  
-%c<IX>z9  
7N8H)X  
} q ?j|K|%   
"?}uQ5f  
5N7H{vT_  
public String getSSiteURL() JgRYljQi2  
{ _c(4o:  
return sSiteURL; Td\o9  
} ^_+XDO  
)Di \_/G  
I s57F4[}  
public void setSSiteURL(String value) dE`-\J  
{ |AhF7Mj*  
sSiteURL = value; /1w2ehE<  
} j+4H}XyE  
El2e~l9  
T? ,P*l  
public String getSFilePath() {r85l\u)Q\  
{ xG2+(f#C1  
return sFilePath; d' >>E  
} &K+0xnUH  
_~'+Qe_o$5  
9SQ4cv*2  
public void setSFilePath(String value) X|LxV]  
{ ksR1k vTm  
sFilePath = value; ?`_jFj+<\S  
} U977#M Xf  
TCKu,}s  
Rf-[svA  
public String getSFileName() =}!Mf'  
{ [V8fu qE>  
return sFileName; (oz$B0HO:  
} vdDludEv  
+UN<Zp7I/  
0IkM  
public void setSFileName(String value) :aLT0q!K  
{ ;lX(}2tXW  
sFileName = value; una%[jTc  
} sM[I4 .A3  
}G<T:(a  
&;TJ~r#K  
public int getNSplitter() `6Qdfmk=  
{ J8a*s`ik  
return nSplitter; FyoEQ%.bI  
} qml2XJ>  
a&{X!:X  
<+j)P4O4  
public void setNSplitter(int nCount) {:nQl}  
{ LjFqZrH  
nSplitter = nCount; C#V ~Y  
} h0vob_Fdl  
} RC#C\S6  
BKa- k!  
#:x4DvDkR  
/* V D?*h  
**Utility.java ?|{XZQ~  
*/ J T# d(Y  
package NetFox; 2Se?J)MN  
H5cV5E0  
Z=5qX2fy1*  
public class Utility { $h[Q Q-  
Lw7=+h)  
X.F^$  
public Utility() <Peebv&v  
{ RZp cXv  
HS>f1!  
nR>r2wMk@  
} b IW'c_ ,  
ma$Prd  
//线程睡眠 s^OO^%b  
public static void sleep(int nSecond) x3ERCqTR  
{ \'CN  
try{ 3ss6_xd+  
Thread.sleep(nSecond); ^I6^g  
} 'uDjFQX  
catch(Exception e) 5BkV aF7Th  
{ $2D uB  
e.printStackTrace (); >evS} O6  
} iJxQB\x  
} )QagS.L{z  
nfW&1a  
//日志 Z+`{7G?4m  
public static void log(String sMsg) +|Hioq* ,t  
{ g42)7  
System.err.println(sMsg); 39F O f  
} !  Z`0(d  
:4S%'d7  
d1@%W;qX!  
public static void log(int sMsg) FOwDp0  
{ )Rat0$6  
System.err.println(sMsg);  =$8nUX`  
} P #F=c34u  
} p,pR!qC>  
)?M9|u  
g[>\4B9t  
/* [OTJVpC  
**TestMethod.java o`zr>  
*/ depYqYK7G  
package NetFox; ]9=h%5Ji>  
LWsP ya  
_{vkX<s  
public class TestMethod { %S` v!*2  
"TV(H+1,z  
GhY1k";  
public TestMethod() l:6,QaT1  
{ ///xx/weblogic60b2_win.exe 0,s$T2  
try{ ' /Bidb?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1QZ&Mj^^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w:Jrmx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 22<0DhJ  
fileFetch.start(); N!Qg;(  
} BYW^/B Y)  
catch(Exception e){e.printStackTrace ();} `s '#  
b96%")  
<D&)OxEn\  
} &~UJf4b|A  
i`/+,<  
FG3UZVUg9  
public static void main(String[] args) 6qe*@o  
{ e}@)z3Q<l  
new TestMethod(); KV|}#<dD  
} V>64/  
} ~'5  
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