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http断点续传简单实现(java)

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/* ?WHf%Ie2(  
**SiteFileFetch.java QOo'Iv+EL  
*/ ('SId@  
package NetFox; Qw:!Rw,x  
import java.io.*; E0R6qS:'  
import java.net.*; >> "gb/x,  
\?>M?6D  
IC&P-X_aP  
public class SiteFileFetch extends Thread { 'Zp{  
i ? ~-%  
n'v\2(&uYN  
SiteInfoBean siteInfoBean = null; //文件信息Bean -z~!%4 a  
long[] nStartPos; //开始位置 Ac|\~w[\  
long[] nEndPos; //结束位置 iW^J>aKy  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 dgF%&*Il]O  
long nFileLength; //文件长度 R__:~ uv,  
boolean bFirst = true; //是否第一次取文件 } 1e4u{  
boolean bStop = false; //停止标志 UPU$SZAIx  
File tmpFile; //文件下载的临时信息 VJqk0w+  
DataOutputStream output; //输出到文件的输出流 ]vlBYAW'  
R`cP%7K  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) o(oOB  
public SiteFileFetch(SiteInfoBean bean) throws IOException a3<:F2=~\  
{ @2/|rq  
siteInfoBean = bean; OIL8'xY.w  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); NDP" @  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [p9v#\G; [  
if(tmpFile.exists ()) dv>n38&mDQ  
{ ?:J_+? {E  
bFirst = false; H #_Zv]  
read_nPos(); Z;Hkx1  
} M/quswn1  
else ,< x/  
{ *u1q7JFQk  
nStartPos = new long[bean.getNSplitter()]; &jHsFS  
nEndPos = new long[bean.getNSplitter()]; v^b4WS+.:  
} (tX3?[ii  
+ODua@ULFB  
OALNZKP  
yl~_~<s6  
} WJOoDS!i  
+Cw_qS"=  
 ~2"hh$  
public void run() h<U?WtWT-p  
{ +T$Olz  
//获得文件长度 &\N>N7/1  
//分割文件 teg5g|*  
//实例FileSplitterFetch HCs^?s8Pp  
//启动FileSplitterFetch线程 +QU>D:l  
//等待子线程返回 Sp80xV_B  
try{ (c(F1=K  
if(bFirst) ZpVkgX4  
{ rk W7;!  
nFileLength = getFileSize(); >\ Dy  
if(nFileLength == -1) z}ar$}T  
{ cK+TE8ao  
System.err.println("File Length is not known!"); Y=P*   
} 'd+fGx7i  
else if(nFileLength == -2) =Z  
{ V ql4*OJW  
System.err.println("File is not access!"); qT@h/Y  
} <bKtAf  
else z#GZb   
{ r%?-MGc  
for(int i=0;i<nStartPos.length;i++) $+'H000x  
{ :3n@].  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); [i`  
} 4GRD- f[  
for(int i=0;i<nEndPos.length-1;i++) HU $"o6ap  
{ ;o!p9MEpz;  
nEndPos = nStartPos[i+1]; CJ\a7=*i  
} |#@7$#j  
nEndPos[nEndPos.length-1] = nFileLength; U=.PL\  
} G;l7,1;MU:  
} z l@^[km{  
 2h   
J,yKO(}<C  
//启动子线程 (`.OS)&  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XP@dg4Z=z  
for(int i=0;i<nStartPos.length;i++) ,Z@#( =f  
{ R+M=)Z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g#J aw|N  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 35& ^spb  
nStartPos,nEndPos,i); a{]=BY oL  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \X8b!41  
fileSplitterFetch.start(); vFVUdxPOw  
} zFq%[ X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !4vb{AH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fHup&|.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4!/JN J  
nEndPos = " + nFileLength); UphTMyn3  
// fileSplitterFetch[nPos.length-1].start(); <kK>C8+  
7AV{ h[J  
2tq2   
//等待子线程结束 =Z^5'h~  
//int count = 0; Y@+Rb  
//是否结束while循环 z qeQ  
boolean breakWhile = false; j>\c > U  
r<UVO$N  
G)Gp}4gV}  
while(!bStop) _uQ]I^'D  
{ 1INX#qTZ  
write_nPos(); z'q~%1t  
Utility.sleep(500); n%&L&G  
breakWhile = true; Ay16/7h@hi  
p R'J4~  
IOl_J>D]F  
for(int i=0;i<nStartPos.length;i++) X.fVbePxUU  
{ n[3z_Q I  
if(!fileSplitterFetch.bDownOver) Qg*\aa94  
{ U**8^:*y#:  
breakWhile = false; "6f`hy  
break; /f3/}x!po  
} {@InOo!4w]  
} ^[?y 2A:  
if(breakWhile) -tg|y  
break; p;+O/'/j  
N[I@}j  
kTb$lLG\xk  
//count++; UBaXS_c\  
//if(count>4) ku]5sd >b  
// siteStop(); cc[(w #K  
} ipv5JD[  
=w$&n%~  
3B1\-ry1M  
System.err.println("文件下载结束!"); pDR~SxBXr  
} {"ST hTZ  
catch(Exception e){e.printStackTrace ();} )eyzHB,H  
} U]3!"+Y1P  
hd)Jq'MCS  
54_}9_g  
//获得文件长度 }'oU/@yG  
public long getFileSize() Z.\q$U7'9  
{ ;I>nA6A  
int nFileLength = -1; NHd@s#@  
try{ KL&/Yt   
URL url = new URL(siteInfoBean.getSSiteURL()); ")Fd'&58  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?@b6(f xX  
httpConnection.setRequestProperty("User-Agent","NetFox"); >yO/p(/;jR  
vzIo2 ,/7  
S<nF>JRJa  
int responseCode=httpConnection.getResponseCode(); l/N<'T_G  
if(responseCode>=400) ZJ/528Ju  
{ ?v2_7x&  
processErrorCode(responseCode); /q9I^ztV  
return -2; //-2 represent access is error A,~3oQV  
} 5|H;%T 3_  
V!Wy[u  
UleT9 [M  
String sHeader; Tv``\<   
!nBbt?*  
k~tEUsv  
for(int i=1;;i++) 4Q|>k )H  
{ WcN4ff-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :aNjh  
//Utility.log(in.readLine()); |bnd92fvks  
sHeader=httpConnection.getHeaderFieldKey(i); ]v ${k  
if(sHeader!=null) 8+'}`  
{ ;(NTzBq!1  
if(sHeader.equals("Content-Length")) Z0<Vss  
{ kF|$oBQ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PL:(Se%  
break; '.Y,VJaL  
} >dAl*T  
} IK -vcG  
else S@qPf0dL<  
break; K"!rj.Da  
} &f.5:u%{b  
} @@ Q4{o  
catch(IOException e){e.printStackTrace ();} zIc6L3w$  
catch(Exception e){e.printStackTrace ();} DsdM:u*s  
6r~9$IM  
b^W&-Hh  
Utility.log(nFileLength); w~]2c{\Qz  
P27Ot1px  
C @Ts\);^  
return nFileLength; 3qWrSziD  
} }i+C)VUX   
(qA F2&  
db )2>  
//保存下载信息(文件指针位置) 2Io| ?  
private void write_nPos() :|j[{;asY  
{ ~?/7: S  
try{ DI0& _,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); aCU[9Xr?  
output.writeInt(nStartPos.length); PF4[;E S'  
for(int i=0;i<nStartPos.length;i++) UynGG@P@  
{ A;U c&G  
// output.writeLong(nPos); QYA4C1h'  
output.writeLong(fileSplitterFetch.nStartPos); QytO0K5  
output.writeLong(fileSplitterFetch.nEndPos); ?1\5X<|,  
} k5RzW4zq;  
output.close(); ( fFrX_K]  
} |gk*{3~y  
catch(IOException e){e.printStackTrace ();} |.; N_i  
catch(Exception e){e.printStackTrace ();} ?qQ{]_q1&.  
} 3U6QYD55]]  
LW=qX%o{  
=9&2udV1  
//读取保存的下载信息(文件指针位置) JQ+Mg&&Q  
private void read_nPos() 48p3m) 5  
{ KDN#CU  
try{ L4iWR/&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w hI4@#  
int nCount = input.readInt(); R&uPoY,f  
nStartPos = new long[nCount]; 7] y3<t  
nEndPos = new long[nCount]; /qQx~doK  
for(int i=0;i<nStartPos.length;i++) | 6AR!  
{ icG 9x  
nStartPos = input.readLong(); P}6#s'07~  
nEndPos = input.readLong(); ZRhk2DA#FF  
} )=)N9CRy  
input.close(); &^ERaPynd  
} B} qRz  
catch(IOException e){e.printStackTrace ();} (CQ! &Z8  
catch(Exception e){e.printStackTrace ();} m]DP{-s4  
} kV8R.Baf3  
3n2^;b/]  
Q}&'1J  
private void processErrorCode(int nErrorCode) RrLiH>  
{ 8mr fs%_  
System.err.println("Error Code : " + nErrorCode); 6Emn@Mn=  
} uNf'Zeo  
Nr@,In|JS  
za6 hyd^  
//停止文件下载 R655@|RT  
public void siteStop() R/{h4/+vJ  
{ .3EEi3z6z  
bStop = true; 3g7]$}  
for(int i=0;i<nStartPos.length;i++) 1=]#=)+  
fileSplitterFetch.splitterStop(); $bp'b<jx  
D u<P^CE  
~Dg:siw  
} @.e4~qz\  
} 42 `Uq[5Y  
//负责部分文件的抓取 iu{y.}?  
**FileSplitterFetch.java @G& oUhS  
*/ `y'%dY}$n  
package NetFox;  3B#fnj  
jzi%[c<G  
*r>Y]VG;S  
import java.io.*; 1dr g5  
import java.net.*; K`=U5vG^  
#W:.Fsq  
~U<j_j)z4.  
public class FileSplitterFetch extends Thread { s\.r3U&6  
2 zo>`;l  
c%<81Y=  
String sURL; //File URL S*r }oX0  
long nStartPos; //File Snippet Start Position ~,W|i  
long nEndPos; //File Snippet End Position tT`S" 9T  
int nThreadID; //Thread's ID aaVq>$G 3  
boolean bDownOver = false; //Downing is over .WglLUJ:Z  
boolean bStop = false; //Stop identical L <  
FileAccessI fileAccessI = null; //File Access interface "P5,p"k:)  
.==c~>N  
`~axOp9N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @>`N%wH'  
{ , -])[u  
this.sURL = sURL; OfLj 4H 6Q  
this.nStartPos = nStart; 6T"5,Q</h  
this.nEndPos = nEnd; FkaQVT  
nThreadID = id; )m-(-I  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z){fie4WM  
} iLdUus!  
g9GPy U  
=j_4!^  
public void run() !rx5i  
{ p+I`xyk  
while(nStartPos < nEndPos && !bStop) :t;\`gQoS  
{ 6/a%%1c1  
 w&U28"i>  
:hHKm|1FE  
try{ UeUOGf ,  
URL url = new URL(sURL); Na\&}GSf^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jcePSps]  
httpConnection.setRequestProperty("User-Agent","NetFox"); "97sH_ ,  
String sProperty = "bytes="+nStartPos+"-"; f`}u9!jVR  
httpConnection.setRequestProperty("RANGE",sProperty); jp-(n z\  
Utility.log(sProperty); QIwO _[Q  
USE!  
GWx?RIKF  
InputStream input = httpConnection.getInputStream(); eT F s9$  
//logResponseHead(httpConnection); H1 ev W  
45+kwo0  
MNfc1I_#  
byte[] b = new byte[1024]; V(G{_>>  
int nRead; [CnoMN  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @ /e{-Q  
{ 8v)Z/R-  
nStartPos += fileAccessI.write(b,0,nRead); kaZcYuT.9  
//if(nThreadID == 1) gYL#} )g  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DUf . F  
} %z1hXh#+  
^]LWcJ?"^!  
CIR2sr0a  
Utility.log("Thread " + nThreadID + " is over!"); h#h)=;  
bDownOver = true; ud(w0eX  
//nPos = fileAccessI.write (b,0,nRead); enMHKN g  
} Zf)<)o*  
catch(Exception e){e.printStackTrace ();} >wV2` 6  
} ++kVq$9@y  
} O|;|7fCB\  
6%VRQ#g!  
]xJ2;{JWsO  
//打印回应的头信息 J@N q  
public void logResponseHead(HttpURLConnection con) K>+c2;t;  
{ En+`ZcA\z  
for(int i=1;;i++) }g.)%Bw!  
{ ovtZHq/  
String header=con.getHeaderFieldKey(i); cMUmJH  
if(header!=null) Xt*h2&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V=GP_^F  
Utility.log(header+" : "+con.getHeaderField(header)); )=h+5Z>E1  
else g*U[?I"sC  
break; (S j?BZjC  
} _t7aOH  
} -A8CW9|mk  
~:A=o?V2  
~RM_c  
public void splitterStop() xqKj&RuLu  
{ [MM`#!K%  
bStop = true; uY )|   
} JOq&(AZe  
0bIhP,4&  
grCz@i  
} yzCamm4~0  
o 3 G*   
:2&W9v  
/* ma2-66M~j  
**FileAccess.java _nW#Cl~  
*//文件访问(定位,写) r/ LgmVRn  
package NetFox; \g;-q9g;O  
import java.io.*; c(S66lp  
>x1?t  
[1`&\C_E  
public class FileAccessI implements Serializable{ 4q^'MZm1  
DmpD`^?-L  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yFqB2(Dv  
RandomAccessFile oSavedFile; GA)t!Xg^  
long nPos; , rc %#eF  
>^KO5N-:4  
*p%=u>?&  
public FileAccessI() throws IOException 8DJoQl9  
{ pj'[ H  
this("",0); =I9RM9O<  
} 7pz #%Hf  
sZPA(N?  
FAd4p9[Y  
public FileAccessI(String sName,long nPos) throws IOException }7|UA%xz  
{ lxD~[e  
oSavedFile = new RandomAccessFile(sName,"rw"); LZ*ZXFIg  
this.nPos = nPos; 64-;| k4F  
oSavedFile.seek(nPos); w ]$Hr   
} h>'Mh;+  
6<C|O-  
_QOZ`st  
public synchronized int write(byte[] b,int nStart,int nLen) nx'D&, VX  
{ -]~vE fq+T  
int n = -1; *U^7MU0  
try{ Wi{ jC?2Q  
oSavedFile.write(b,nStart,nLen); EJ`"npU  
n = nLen; wtnC^d$  
} Bgj^n{9x  
catch(IOException e) <MBpV^Y}  
{ -eoXaP{[  
e.printStackTrace (); a{7'qmN1  
} V17SJSC-  
$4&e{fLt|v  
x.~AvJ  
return n; 5QUL-*t  
} .:=G=v=1  
.+ g8zbD4  
mXXU{IwUe  
} |.Y}2>{  
"_  i:  
)>|x2q  
/* j UCrj'  
**SiteInfoBean.java hUGP3ExC*  
*/ }&O}t{gS*  
package NetFox; S4FR=QuVQC  
W #kOcw  
R<n'v.~"A  
public class SiteInfoBean { xF8^#J6>  
1MnT*w   
jou741  
private String sSiteURL; //Site's URL m3E`kW |  
private String sFilePath; //Saved File's Path Wc qUF"A  
private String sFileName; //Saved File's Name +Q+>{HK  
private int nSplitter; //Count of Splited Downloading File wXnluE  
y)e8pPDG  
]3iQpL  
public SiteInfoBean() i917d@r(<  
{//nSplitter的缺省值为5 zBTyRL l  
//default value of nSplitter is 5 I[v6Y^{q  
this("","","",5); &;]KntxB  
} R-V4Ju[:  
vhOX1'  
K/Qo~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9d_ Zdc  
{ f,}9~r #  
sSiteURL= sURL; X1PXX!]lo[  
sFilePath = sPath; oF0BBs$  
sFileName = sName; p`-Oz]  
this.nSplitter = nSpiltter; ic(`Ev  
(!B1} 5"  
nkn4VA?"  
} .P^&sl*J  
yTb#V"eR  
JcDcYB  
public String getSSiteURL() 1Vy8TV3D  
{ \DC0`  
return sSiteURL; :@8N${7`$A  
} \&Zp/;n  
i~0x/wSl_  
.Do(iYO.L  
public void setSSiteURL(String value) T z?0E"yx  
{ 70BLd(?  
sSiteURL = value; 3q*p#l~  
} Uop`)  
sOUQd-!"  
nWz7$O  
public String getSFilePath() ;S.o` z1GI  
{ k zuI<DW  
return sFilePath; zIT)Hs5  
} ;*}tbh3;.  
(764-iv(  
L.tW]43K  
public void setSFilePath(String value) fS#I?!*}  
{ 6( 0ME$  
sFilePath = value; j|Hyv{sM  
} $4ZjNN@  
9 m`VIB  
]]^eIjg>a6  
public String getSFileName() 6k-  
{ 'BO MFp7c  
return sFileName; bc}BQ|Q  
} 2M o oqJp  
O; #qG/b1  
\\UOpl  
public void setSFileName(String value) (@&+?A"6`  
{ QRKr2:o{  
sFileName = value;  :qe.*\ c  
} ?hh#@61  
1@S(v L3a  
NwbX]pDT  
public int getNSplitter() EwX:^1f  
{ bDADFitSo  
return nSplitter; JK y0 6I  
} <A`zK  
xjK@Q1MJ  
+ko-oZ7V  
public void setNSplitter(int nCount) # m;|QWW  
{ |\3X7)^8D  
nSplitter = nCount; E,p4R%:$@1  
} PyQ P K,  
} }u?DK,R  
>,}SP;  
&\>.j|  
/* RoYwZX~  
**Utility.java rMEM$1vPU  
*/ 5|_El/G  
package NetFox; 3K{G=WE$  
6s(.u l  
%&}gt+L(M  
public class Utility { fZka$ 4  
vMv? fE"  
f)#rBAkt  
public Utility() eB2a1<S&@  
{ R.P|gk  
q'1 86L87  
8ZL9>"%l  
} X(M|T]`b:  
G{]tB w  
//线程睡眠 gPqdl6#c  
public static void sleep(int nSecond) U]}f]GK  
{ >#[,OU}N  
try{ o/4U`U)Q0v  
Thread.sleep(nSecond); uG,*m'x']  
} |kK_B :K  
catch(Exception e) 26B+qXEt  
{ 94Q?)0W$  
e.printStackTrace (); *w5xC5*  
} *wp>a?sG\  
} _Y _v&  
C2(VYw  
//日志 JS2h/Y$  
public static void log(String sMsg) w tSX(LN Y  
{ n =qu?xu  
System.err.println(sMsg); |!hN!j*)  
} + C'<*  
Lm1  -  
ESi'3mbeC  
public static void log(int sMsg) Gph:'3 *X  
{ ?M9?GodbP.  
System.err.println(sMsg); JrNqS[c/  
} pKNrEq  
} *iiyU}x  
/5N`E uw  
,.]1N:   
/* /ei(Q'pc[  
**TestMethod.java 6xiCTs0@  
*/ N'n\_x  
package NetFox; :878q TB  
KvY1bMU!  
*|Bt!  
public class TestMethod { J u"K"  
Lpv,6#m`)  
^t}8E2mq  
public TestMethod() Gy6PS{yY6t  
{ ///xx/weblogic60b2_win.exe &ieb6@RO`Q  
try{ " 3tk"#.#  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AR3v,eOs  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y134m  
SiteFileFetch fileFetch = new SiteFileFetch(bean); yt[*4gF4  
fileFetch.start(); Xv2Q8-}w  
} ;i-<dAV8B  
catch(Exception e){e.printStackTrace ();} V(wANvH  
'dJ(x  
0HPqoen$  
} H$rNT/C  
lN~u='Kc  
z$Z{ LR  
public static void main(String[] args) \'.|7{Xu  
{ s6(bTO.  
new TestMethod(); `G "&IQ8.  
} F2!]T=  
} ;!pSYcT,  
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