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http断点续传简单实现(java)

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/* J%x\=Sv  
**SiteFileFetch.java SZ,YS 4M  
*/ |y0(Q V  
package NetFox; CDP U\ZG  
import java.io.*; { OXFN;2  
import java.net.*; ,q}ML TS i  
Z Uox Mm  
\6R,Nq  
public class SiteFileFetch extends Thread { :-/M?,Q"  
t .7?  
BI3@|,._N  
SiteInfoBean siteInfoBean = null; //文件信息Bean Lv| q  
long[] nStartPos; //开始位置 n?- })  
long[] nEndPos; //结束位置 {so `/EWa  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &Xf^Iu  
long nFileLength; //文件长度 3BtaH#ZY  
boolean bFirst = true; //是否第一次取文件 bn!HUM,  
boolean bStop = false; //停止标志 /H8g(  
File tmpFile; //文件下载的临时信息 H."EUcE{  
DataOutputStream output; //输出到文件的输出流 ~:Ll&29i  
SKkUU^\#R`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) j`~Ms>  
public SiteFileFetch(SiteInfoBean bean) throws IOException kQEy#JQmB  
{ KwPOO{4]g  
siteInfoBean = bean; aX5 z&r:{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5]AC*2(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); - `p4-J!Fy  
if(tmpFile.exists ()) n[G&ksQI  
{ (NF~Ck$#q  
bFirst = false; _3TY,l~  
read_nPos(); )N7Y^CN~  
} 4\Tl\SZ?  
else sj HrPs e  
{ I'uSp-Sfy  
nStartPos = new long[bean.getNSplitter()]; mt,OniU=Q  
nEndPos = new long[bean.getNSplitter()]; M<kj_.  
} B56L1^ 7  
!,6c ~ w  
~N<4L>y<  
z([ v%zf  
} X]wRwG  
3'cE\u  
]pH-2_  
public void run() 23Nw!6S  
{ ;\14b?TUH  
//获得文件长度 LUM@#3&  
//分割文件  |8My42yf  
//实例FileSplitterFetch u~WVGjoQ  
//启动FileSplitterFetch线程 EfCx`3~EX  
//等待子线程返回 TFkZpe;  
try{ A Q'J9  
if(bFirst) g^}8:,F_  
{ u>kN1kQ8  
nFileLength = getFileSize(); 8,? h~prc  
if(nFileLength == -1) {q `jDDM  
{ q|!-0B @  
System.err.println("File Length is not known!"); e=B|==E10M  
} 6L"%e!be6  
else if(nFileLength == -2) qz0;p=$8Z  
{ Y]/% t{Y  
System.err.println("File is not access!"); VGpWg rmHk  
} O(D ~_O.  
else i} .&0Fp  
{ lT&eJO~?5  
for(int i=0;i<nStartPos.length;i++) uRZZxZ  
{ /v- 6WSN  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }\\KYyjY  
} }:us:%  
for(int i=0;i<nEndPos.length-1;i++) @?yX!_YC  
{ KKiE@_z  
nEndPos = nStartPos[i+1]; 18+)`M-5o  
} w5Ay)lz  
nEndPos[nEndPos.length-1] = nFileLength; BD_Iz A<wK  
} .Le?T&_  
} WtG~('g>&  
GO` Ru 8  
$\]&rZVi  
//启动子线程 ]:4*L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ju96#v+:  
for(int i=0;i<nStartPos.length;i++)  @~!wDDS  
{ 8FKXSqhVM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5=v}W:^v.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RS)tO0  
nStartPos,nEndPos,i); $~VRza 8Q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K 1 a\b"  
fileSplitterFetch.start(); 1IC~e^"  
} 5ni~Q 9b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T 6)bD&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6p?,(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5nT"rA  
nEndPos = " + nFileLength); j bVECi-  
// fileSplitterFetch[nPos.length-1].start(); iOU6V  
mz,  
3I)VHMC  
//等待子线程结束 gkES5Q  
//int count = 0; ="Ho%*@6  
//是否结束while循环 (tIo:j  
boolean breakWhile = false; gy#/D& N[  
xJ>fm%{5  
OB Otuu.  
while(!bStop) Fl kcU `j  
{ 9 7GV2]-M  
write_nPos(); YG3J$_?y0  
Utility.sleep(500); 'gC_)rK*  
breakWhile = true; kCR_tn 4  
o4m\~as)Y  
/178A;J y  
for(int i=0;i<nStartPos.length;i++) H*ow\ Ct  
{ ([SU:F!uW(  
if(!fileSplitterFetch.bDownOver) }001K  
{ bCo7*<I4  
breakWhile = false; fZ0M%f  
break; (.D~0a JU  
} Si8pzd  
} }uJu>'1[G  
if(breakWhile) ABQ('#78  
break; ';3{T:I  
C-Q28lD}f  
fI&t]   
//count++; U>]$a71  
//if(count>4) _I@9HC 4  
// siteStop(); }=<  
} YC++& Nk  
;j[>9g  
h"X;3b^ m  
System.err.println("文件下载结束!");  .E`\MtA  
} |bTPtrT8  
catch(Exception e){e.printStackTrace ();} T ]t'39  
} ZA0mz 65  
hIy~B['  
B"h#C!E  
//获得文件长度 63\/ * NNB  
public long getFileSize() 7HIeJ  
{ w65K[l;2  
int nFileLength = -1; K2TcOFQ  
try{ J]{QB^?  
URL url = new URL(siteInfoBean.getSSiteURL()); ]^h]t~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  Uwf +  
httpConnection.setRequestProperty("User-Agent","NetFox"); yv t.  
L 6 c 40  
> V-A;S:  
int responseCode=httpConnection.getResponseCode(); O_ `VV*  
if(responseCode>=400) } Yb[   
{ IpYM;tYw&  
processErrorCode(responseCode); pMw*9s X  
return -2; //-2 represent access is error Q6PHpaj  
} 4!Fo$9  
NjVYLn<.r  
'@o;-'b  
String sHeader; ]<ldWL  
) i;1*jK  
~IYUuWF(  
for(int i=1;;i++) - Ajo9H  
{ zQcL|  (N  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r)y=lAyF>  
//Utility.log(in.readLine()); Y~c|hfL  
sHeader=httpConnection.getHeaderFieldKey(i); J\+0[~~  
if(sHeader!=null) &XIt5<$~R  
{ [w0QZyUn  
if(sHeader.equals("Content-Length")) |XQIfW]A  
{ 3@kf@ Vf  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bmr>n6|  
break; uGwm r  
} .B7,j%1r  
} \H1( PA  
else mWoAO@}Y  
break; o} J&E{Tk  
} "|EM;o  
} /s x@$cvW  
catch(IOException e){e.printStackTrace ();} JZ)RGSG i  
catch(Exception e){e.printStackTrace ();} )#?"Gjf~  
j'Gt&\4  
PQy4{0 _  
Utility.log(nFileLength); a!a-b~#cx  
T -.%  
z>LUH  
return nFileLength; /Lfm&;  
} ;Y 00TGU  
2^r <{0@n  
(up~[  
//保存下载信息(文件指针位置) w mn+  
private void write_nPos() ]OM"ZG/^  
{ c/D+|X*  
try{ ?4+9fE<Q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); } df W%{  
output.writeInt(nStartPos.length); 5 h-@|t  
for(int i=0;i<nStartPos.length;i++) ^]H5h]U '  
{ f86XkECZ;`  
// output.writeLong(nPos); y&6FybIz  
output.writeLong(fileSplitterFetch.nStartPos); `95r0t0hh\  
output.writeLong(fileSplitterFetch.nEndPos); abuh`H#  
} Vx$\hcG  
output.close(); WJQvB=D&  
} +9M^7/}H  
catch(IOException e){e.printStackTrace ();} :0Bq^G"ge  
catch(Exception e){e.printStackTrace ();} \HqNAE2T  
} t)~"4]{*}D  
SEo'(-5  
tI`Q/a5@  
//读取保存的下载信息(文件指针位置) $mu^G t  
private void read_nPos() *1 uKr9  
{ 52%2R]G!  
try{ vmU@^2JSJ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vx1c,8  
int nCount = input.readInt(); '.on)Zd.  
nStartPos = new long[nCount]; Dt}JG6S  
nEndPos = new long[nCount]; M\o9I  
for(int i=0;i<nStartPos.length;i++) ZT'`hK_up  
{ }u\])I3  
nStartPos = input.readLong(); $:8x(&+/@  
nEndPos = input.readLong(); V\>K]mwD  
} 1ct;A_48  
input.close(); /$i.0$L  
} <NR#Y%}-V  
catch(IOException e){e.printStackTrace ();} bfFeBBi  
catch(Exception e){e.printStackTrace ();} zZ7;jyD  
} b+%f+zz*h  
3_ r*y9l  
r A`V}>Xj  
private void processErrorCode(int nErrorCode) CnU*Jb  
{ uW=k K0E  
System.err.println("Error Code : " + nErrorCode); o m^0}$V  
} A#K14Ayr  
ERUz3mjA/  
]_Vx{oT7  
//停止文件下载 ~Y`ldL  
public void siteStop() ,`|3KE9  
{ lsJSYJG&  
bStop = true; LzG%Z1`  
for(int i=0;i<nStartPos.length;i++) A0/"&Ag]  
fileSplitterFetch.splitterStop(); &TnS4O  
S*==aftl(  
rx'RSo#1O  
} cA2V2S)  
} - \ 5v^l  
//负责部分文件的抓取 s6H]J{1F  
**FileSplitterFetch.java RM]\+BK  
*/ o\[~.";Z  
package NetFox; NokU) O;x  
]q;Emy  
@fHi\W2JG  
import java.io.*;  '<jyw   
import java.net.*; u#Pa7_zBj]  
#pT"BSz]  
Vrjc~>X  
public class FileSplitterFetch extends Thread { -c_74c50  
viW!,QQ(S  
]}Mj)J"m  
String sURL; //File URL US+Q~GTA  
long nStartPos; //File Snippet Start Position .?D7dyU l1  
long nEndPos; //File Snippet End Position f~t:L, \,  
int nThreadID; //Thread's ID ^?-:'<4q$  
boolean bDownOver = false; //Downing is over Qk0R a_  
boolean bStop = false; //Stop identical V3 9g,=`b%  
FileAccessI fileAccessI = null; //File Access interface ?[VM6- &  
-j+UMlkB  
4~ q5,^kgB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pf2[ , v/  
{ ]jtK I4  
this.sURL = sURL; J}*,HT*  
this.nStartPos = nStart; qaqBOHI6G  
this.nEndPos = nEnd; z#8~iF1  
nThreadID = id; 'OE&/ C [  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p?{Xu4(  
} ED2a}Tt>Z  
O)C\v F#  
zE336  
public void run() N"pc,Q\xU  
{ H~oail{EQ  
while(nStartPos < nEndPos && !bStop) 5/q}`T9i%7  
{ cCSs  
fWCo;4<5?  
x5|I  
try{ xN>npP   
URL url = new URL(sURL); GX)u|g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w ~.f  
httpConnection.setRequestProperty("User-Agent","NetFox"); _A M*@|p,  
String sProperty = "bytes="+nStartPos+"-"; l3KVW5-!gS  
httpConnection.setRequestProperty("RANGE",sProperty); !xzeMVI  
Utility.log(sProperty); O6Vtu Ws%  
$CxKuB(  
Yw22z #K  
InputStream input = httpConnection.getInputStream(); sWQfr$^A  
//logResponseHead(httpConnection); `uq8G  
&Q9qq~  
KLU-DCb%  
byte[] b = new byte[1024]; bADnW4N`6;  
int nRead; 8J*"%C$qe  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TIx|L  
{ Eou~P h*t  
nStartPos += fileAccessI.write(b,0,nRead); CWf / H)~  
//if(nThreadID == 1) a[v0%W ]u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5uGqX"  
} ZWii)0'PV  
t#yk ->,  
G !<Z.]  
Utility.log("Thread " + nThreadID + " is over!"); ~Xw"}S5  
bDownOver = true; -B>++r2A^  
//nPos = fileAccessI.write (b,0,nRead); 5(Cl1Yse=r  
} t![7uU.W  
catch(Exception e){e.printStackTrace ();} tN[L@t9#cr  
} ylUrLQ\  
} x"eRJii?  
7.-V-?i  
anuL1f XO  
//打印回应的头信息 BoA/6FRi[  
public void logResponseHead(HttpURLConnection con) R7]l{2V#^  
{ k=2Lo  
for(int i=1;;i++) =31"fS@  
{ *zNYZ#  
String header=con.getHeaderFieldKey(i); V @rI`~$  
if(header!=null) %`k6w3qI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [l:x'_y  
Utility.log(header+" : "+con.getHeaderField(header)); VJ84?b{c W  
else pb^i^tA+A  
break; m9)p-1y@5  
} 6f;fx}y  
} uzXCIv@  
iz5CAxm  
'#! gh?  
public void splitterStop() vrl;"Fm+  
{ d[[]P X  
bStop = true; cD@(/$wt  
} )W|w C#  
-T!f,g3vW  
~"dA~[r L  
} 4pe'06:  
_t:$XJ`bTk  
6L:x^bM  
/* r)qnl9?;`]  
**FileAccess.java "vA}FV%tRq  
*//文件访问(定位,写) jnd[6v=C7-  
package NetFox; 5NBV[EP  
import java.io.*; U6=..K!q  
\%u3  
}{M#EP8q+  
public class FileAccessI implements Serializable{ PxF <\pu&  
U!T~!C^  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WJ)z6m]  
RandomAccessFile oSavedFile; w'L\?pI  
long nPos; mrTlXXz  
A+HF@Uw}^  
\ Fl+\?~D  
public FileAccessI() throws IOException h"lX 4  
{ $GYm6x\4  
this("",0); ko1J094Y%  
} !P ~_Dl2d  
EQ2#/>  
PiYY6i0  
public FileAccessI(String sName,long nPos) throws IOException 6\L0mcXR!  
{ @HT% n  
oSavedFile = new RandomAccessFile(sName,"rw"); {-ZFp  
this.nPos = nPos; jNu9KlN  
oSavedFile.seek(nPos); Yv hA_v  
} z MLK7+  
b6W2^tr-  
Y_}mYvJW  
public synchronized int write(byte[] b,int nStart,int nLen) uB |Ss  
{ `/_o!(Z`  
int n = -1; r/& sub"X  
try{ ktI/3Mb@  
oSavedFile.write(b,nStart,nLen); n 9\ C2r  
n = nLen; )i q-yjO6  
} X7[^s $VK  
catch(IOException e) YNYx>Ue  
{ pa#d L!J  
e.printStackTrace (); 5>VY LI  
} "-_fv5jL  
p/(~IC "!J  
t'9*R7=  
return n; u?>B)PW  
} N03G>fZ  
V7#Ffi  
6W@UJx}w5  
} L{:9Cx!F  
Tskq)NU  
Pa(^}n|  
/* `IOs-%s  
**SiteInfoBean.java  pnMEB,)  
*/ MzPzqm<  
package NetFox; rI^zB mrr  
r~+\ Y"rM  
g wz7krUTe  
public class SiteInfoBean { rX*H)3F  
Jm|+-F@I  
A"`foI$0  
private String sSiteURL; //Site's URL %cCs?ic  
private String sFilePath; //Saved File's Path "8'@3$>R=  
private String sFileName; //Saved File's Name s?zAP O8Sz  
private int nSplitter; //Count of Splited Downloading File }>)@WL:q  
fKp#\tCc y  
^BUYjq%(`  
public SiteInfoBean() c;{Q,"9U  
{//nSplitter的缺省值为5 |"XPp!_uN  
//default value of nSplitter is 5 :]rJGgK#  
this("","","",5); 3VI4X  
} lAzj N~V  
*"WDb|PBb  
J\J?yo 6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7uT:b!^f[  
{ a UxGzMZ  
sSiteURL= sURL; [v$0[IuY,  
sFilePath = sPath; a,3j,(3  
sFileName = sName; cHcmgW\4  
this.nSplitter = nSpiltter; J~B<7O<?!1  
7Q7-vx  
e2z h&j  
} $p#%G#T  
kgy:Q'  
4VHqBQ4  
public String getSSiteURL() PGYXhwOI  
{ .w> 4  
return sSiteURL; L,SGT8lL  
} dcLA1sN,  
%ThyOl@O  
fq5_G~c =  
public void setSSiteURL(String value) ONx( ]  
{ }K1JU`Lz  
sSiteURL = value; "8 ~:[G#  
} Glxuz0]  
=1O<E  
O$D'.t  
public String getSFilePath() iv?gZg   
{ 4 SHU  
return sFilePath; Rop'e8Q  
} MS>t_C(  
O:TlIJwW  
Q?8R[i  
public void setSFilePath(String value) CqHK%M  
{ Rp*R:3 C  
sFilePath = value; nt;haeJ  
} @mE)|.f  
af#pR&4}   
ix W@7m  
public String getSFileName() t| 9 GS|  
{ |u0( t,T  
return sFileName; AtU v71D:  
} CNQC^d\ h  
TT50(_8  
XW -2~?$  
public void setSFileName(String value) X/z6"*(|/  
{ zUkN 0  
sFileName = value; YoN*:jB<M  
} bV edFm  
?pYKZg /c  
U7!.,kR-  
public int getNSplitter() %|^OOU}  
{ )x}l3\s  
return nSplitter; %{(x3\ *&  
} hX`hs- *qM  
:ml2.vP  
56e r`=ms  
public void setNSplitter(int nCount) ~/8M 3k/  
{ 7M<'ddAN  
nSplitter = nCount; `W dD8E  
} 1QcT$8HA  
} gXonF'  
GuGOePV  
@HRC \OG  
/* ,ldI2 ]  
**Utility.java %9k!A]KD  
*/ {cB+mh;mJ>  
package NetFox; aFe`_cnG  
{K4+6p  
:C}2=  
public class Utility { ,*&G1|_6  
R+nMy=I%8  
fwrJ!j  
public Utility() ddfs8\  
{ u)ev{)$TM  
JJltPGT~Oa  
A a= u+  
} t~E<j+<2B  
Z.W66\8~}^  
//线程睡眠 s[K^9wz  
public static void sleep(int nSecond) V?P,&c?84  
{ 4Ue_Y 'LmM  
try{ a 4=N9X  
Thread.sleep(nSecond); Cw~RJ^a_  
} cTXri8K_  
catch(Exception e) "S&@F/  
{ iT;@bp  
e.printStackTrace (); DHw&+MY  
} aM@z^<Ub  
} lqowG!3H  
K,6b3kk  
//日志 N0K){  
public static void log(String sMsg) uQ=^~K:Z~  
{ )J_\tv  
System.err.println(sMsg); ew;ur?  
} ]J* ,g,  
-D N8Yb  
cFN'bftH4  
public static void log(int sMsg) EyI}{6~F  
{ 4-kZJ\]  
System.err.println(sMsg); `} m Q  
} JXixYwm  
} ~`GhS<D  
ik"sq}u_]E  
l" q1?kaVg  
/* BnCKSg7V  
**TestMethod.java ed!:/+3e/  
*/ ?E9DXg  
package NetFox; &O)&k  
?9HhG?_x  
+vNZW@_$D  
public class TestMethod { !" JfOu  
yMZHUd  
Ja]?&j  
public TestMethod() Z1ALq5  
{ ///xx/weblogic60b2_win.exe ui "3ak+F  
try{ 'DCFezdf3  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0x11 vr!  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '=E3[0W  
SiteFileFetch fileFetch = new SiteFileFetch(bean); uk9g<<3T  
fileFetch.start(); !PMU O\y  
} & SAH2xR  
catch(Exception e){e.printStackTrace ();} c(U  
[w0/\]o  
@v}B6j b;  
} LuR,f"%2  
$s4Wkq  
_TUk(Qe  
public static void main(String[] args) @)>D))+  
{ uK ("<u|  
new TestMethod(); zf.- I  
} }C  /]  
} :^'O}2NP  
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