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http断点续传简单实现(java)

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/* Znv3h  
**SiteFileFetch.java Gk!06   
*/ G(g.~|=EZ  
package NetFox; ewOd =%  
import java.io.*; zdL"PF  
import java.net.*; #6'x-Z_  
&!@7+'])  
J6WyFtlyLc  
public class SiteFileFetch extends Thread { ^7q qO%  
#- l1(m  
+@U}gk;#c  
SiteInfoBean siteInfoBean = null; //文件信息Bean zlUXp0W  
long[] nStartPos; //开始位置 n<}t\<LG^c  
long[] nEndPos; //结束位置 1Qc>A8SU  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 2|LgUA?<  
long nFileLength; //文件长度 Ewfzjc  
boolean bFirst = true; //是否第一次取文件 j9V*f HK  
boolean bStop = false; //停止标志 kw%vO6"q(  
File tmpFile; //文件下载的临时信息 aBBTcN%'  
DataOutputStream output; //输出到文件的输出流 kM#ZpI&0%  
`t@Rh~B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Pjs L{,  
public SiteFileFetch(SiteInfoBean bean) throws IOException bJ~@ k,'  
{ gc ce]QS  
siteInfoBean = bean; \Ax[/J2aO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $.7Ov|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 1>KZ1Kf  
if(tmpFile.exists ()) h{J=Rq  
{ aSN"MTw.  
bFirst = false; d x/NY1  
read_nPos(); yF~iVt  
} 6N6}3J5  
else qu}&4_`%:V  
{ u?ALZxj?  
nStartPos = new long[bean.getNSplitter()]; q ,C)AZ  
nEndPos = new long[bean.getNSplitter()]; W)RCo}f  
} G2  
>ZE8EL  
<~rf;2LZ  
/2<1/[#  
} y;.U-}e1  
.4t-5,7s%  
?qdZ]M4e  
public void run() M%\=Fb  
{ 12Lc$\3P  
//获得文件长度 I6jDRC0<  
//分割文件 ?3I93Bt7  
//实例FileSplitterFetch F!LVyY"w  
//启动FileSplitterFetch线程 8 2EH'C  
//等待子线程返回 l]bCt b%_  
try{ shn{]Y  
if(bFirst) @TvoCDeI  
{ 8 [z<gxP`?  
nFileLength = getFileSize(); _&U5 u  
if(nFileLength == -1) A9?h*/$  
{ /]_a\x5Ss  
System.err.println("File Length is not known!"); ;RmL'  
} rA">< pH  
else if(nFileLength == -2) P B W.nm  
{ ug|'}\LY  
System.err.println("File is not access!"); }'"4q  
} #dd-rooQuD  
else Ykt{]#  
{ B!;qz[]I  
for(int i=0;i<nStartPos.length;i++) AP2BND9  
{ cAL*Md8+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "TLY:V  
} n#NE.ap$&,  
for(int i=0;i<nEndPos.length-1;i++) SWrt4G  
{ ,X&(BQj h  
nEndPos = nStartPos[i+1]; .y)Y20=o!  
} XDot3)2`  
nEndPos[nEndPos.length-1] = nFileLength; "!fvEE  
} Qd{h3K^hlu  
} A#WvN>  
SEL7,8 Hm  
bnm3 cR:h"  
//启动子线程 miq"3  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gvoo1 Sa  
for(int i=0;i<nStartPos.length;i++) ;&A%"8o  
{ kOQq+_Y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "F$0NYb]I  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WgV'T#*  
nStartPos,nEndPos,i); ftw@nQNU  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #?V7kds]  
fileSplitterFetch.start(); `H^?jX>7  
} -kv'C6gB  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Me.t_)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xv5|j/<~p  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _LOV&83O(  
nEndPos = " + nFileLength); bR0z$~  
// fileSplitterFetch[nPos.length-1].start(); R3[H#*gF<  
AzfYw'^&9  
Mzbbr57n  
//等待子线程结束 B <CK~ybY  
//int count = 0; WX2w7O'R  
//是否结束while循环 J[?7`6\M  
boolean breakWhile = false; u`Sg'ro  
z.xOT;t  
UImd* ;2TE  
while(!bStop) HgY#O r(  
{ _F"o0K!u  
write_nPos(); 'u%;5;%2  
Utility.sleep(500); <f')]  
breakWhile = true; ]t23qA@^2  
2&k5X-Y  
~I_v {  
for(int i=0;i<nStartPos.length;i++) _ i-(` 5  
{ DM73 Nn^5  
if(!fileSplitterFetch.bDownOver) Z6`oGFq  
{ n*HRGJ  
breakWhile = false; .QaHE`e{  
break; gk*Md+  
} DH5]Kzb/  
} m V U(b,  
if(breakWhile) us:V\V  
break; jW?siQO^  
L'*P;z7<  
l$:.bwXXO  
//count++; h /.^iT  
//if(count>4) B!#F!Wk"  
// siteStop(); X`,]@c%C`  
} Ga%x(1U[&  
,z*-93H1  
Gz>M`M`[4  
System.err.println("文件下载结束!"); ]Q%|69H}B  
} syseYt]  
catch(Exception e){e.printStackTrace ();} Yy_o*Ozq  
} z@_ 9.n]  
6*cY[R|q!  
@ eQo  
//获得文件长度 w'Cn3b)`  
public long getFileSize() RCS91[  
{ f a9n6uT  
int nFileLength = -1; cITF=Ez  
try{ :EX H8n&|  
URL url = new URL(siteInfoBean.getSSiteURL()); N~w4|q!]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mJ>@Dh3>G  
httpConnection.setRequestProperty("User-Agent","NetFox"); bhI yq4N  
r%QnV0L^  
U;QN+fF]u  
int responseCode=httpConnection.getResponseCode(); #kuk3}&  
if(responseCode>=400) <MPoDf?h  
{ )bM #s">Y  
processErrorCode(responseCode); @rTAbEk{U  
return -2; //-2 represent access is error @\!9dK-W  
} icX$<lD  
6L2Si4OGjG  
vfh0aW-O  
String sHeader; \[-z4Fxg|'  
LEUD6 M+~t  
kRyt|ryWh  
for(int i=1;;i++) >-~2:d\M3  
{ 0B4&!J  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q$;'Fy%oy  
//Utility.log(in.readLine()); CkJU5D  
sHeader=httpConnection.getHeaderFieldKey(i); xSQ0]vE  
if(sHeader!=null) q0}?F  
{ /eoS$q  
if(sHeader.equals("Content-Length")) D-/aS5wM  
{ OfR\8hAY  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ""dX4^gtU  
break; ~+y0UEtq7  
} /!r#=enG7  
} Vs)%*1><  
else UacGq,  
break; ATeXOe  
} W[dMf!(  
} `mI% Se  
catch(IOException e){e.printStackTrace ();}  n(mS  
catch(Exception e){e.printStackTrace ();} }> 51oBgk_  
e<wRA["  
0P5!fXs*  
Utility.log(nFileLength); 9}4EW4  
.?TPoqs7Z  
"dKYJ&$  
return nFileLength; $J~~.PUXQ  
} +Oae3VFf;  
"! yKX(aTX  
 9"@P.8_  
//保存下载信息(文件指针位置) jJpSn[{  
private void write_nPos() r "^ {?0  
{ %HRFH  
try{ >PsP y.  
output = new DataOutputStream(new FileOutputStream(tmpFile)); a?+Ni|+  
output.writeInt(nStartPos.length); !f(aWrw7e6  
for(int i=0;i<nStartPos.length;i++) S;o U'KOY  
{ )$#r6fQO  
// output.writeLong(nPos); dh7PpuN{  
output.writeLong(fileSplitterFetch.nStartPos); !U,^+"l'GP  
output.writeLong(fileSplitterFetch.nEndPos); -jZP&8dPH  
} /nK)esB1L  
output.close(); bw@Dc T&,  
} S=Ihg  
catch(IOException e){e.printStackTrace ();} @~!1wPvF`I  
catch(Exception e){e.printStackTrace ();} 5-277?  
} seFug  
5(/ 5$u   
+ *YGsM`E9  
//读取保存的下载信息(文件指针位置) BO5gwvyI  
private void read_nPos() @-z#vJ5Qe{  
{ AUloP?24  
try{ 728}K^7:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iA~b[20&  
int nCount = input.readInt(); imx/hz!  
nStartPos = new long[nCount]; u_aln[oIv  
nEndPos = new long[nCount]; 8ycmvpJ  
for(int i=0;i<nStartPos.length;i++) )shzJ9G  
{ O<R6^0B42  
nStartPos = input.readLong(); x M1>kbo|  
nEndPos = input.readLong(); LzEAA{  
} lu^ c^p;  
input.close(); {&Kq/sRz  
} dqMR<Nl&  
catch(IOException e){e.printStackTrace ();} q8:Z.<%8  
catch(Exception e){e.printStackTrace ();} (K$K;f$"r  
} GHHErXT\a  
J&{qe@^  
WgdL^PN(h  
private void processErrorCode(int nErrorCode) ?VMj;+'tr  
{ U~8.uldnF  
System.err.println("Error Code : " + nErrorCode); XpzdvR1  
} w;.'>ORC  
&jgpeFiiC  
]P TTI\n  
//停止文件下载 PN{l)&K2.  
public void siteStop() '3>kDH+  
{ 1#AdEd[  
bStop = true; j+3~  
for(int i=0;i<nStartPos.length;i++) _nR8L`l*z  
fileSplitterFetch.splitterStop(); TEZ^Ia  
khl(9R4a  
/Yk2 |L  
} :&= TE2  
} L~1u?-zu  
//负责部分文件的抓取 &* 4uji  
**FileSplitterFetch.java 3G9YpA_}X  
*/ b#-5b%ON  
package NetFox; dbkccO}WB  
%3e}YQe)  
e~r%8.Wm  
import java.io.*; 5_+vjV;5  
import java.net.*; Xj^6ZJc  
G7k0P-r,0  
UA[2R1}d  
public class FileSplitterFetch extends Thread { #q~SfG  
1<]g7W  
N2_j[Pe  
String sURL; //File URL (NUk{MTX  
long nStartPos; //File Snippet Start Position >n@?F[Y  
long nEndPos; //File Snippet End Position oK h#th  
int nThreadID; //Thread's ID ;T2)nSAqt  
boolean bDownOver = false; //Downing is over wTFM:N  
boolean bStop = false; //Stop identical lgZ3=h  
FileAccessI fileAccessI = null; //File Access interface )5lo^Qb  
Lj"~6l`)  
xm>RLx}9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uROt h_/  
{ tRYMK+  
this.sURL = sURL; oC>QJ(o,8  
this.nStartPos = nStart; =:a H2T*  
this.nEndPos = nEnd; <@n/[ +3  
nThreadID = id; Q3#- q> ;7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lTPo2-j/eK  
} 88}c+V+N!  
: j&M&+  
KO(+%>^R  
public void run() }N5>^y  
{ 4NL Tt K  
while(nStartPos < nEndPos && !bStop) 59";{"sw  
{ -zg,pK$+  
SU"-%}~O#,  
CGIcuHp  
try{ [7?K9r\#  
URL url = new URL(sURL); KyW6[WA9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3%m2$\  
httpConnection.setRequestProperty("User-Agent","NetFox"); yk Sn=0  
String sProperty = "bytes="+nStartPos+"-"; !v|j C  
httpConnection.setRequestProperty("RANGE",sProperty); /-<S FT`  
Utility.log(sProperty); 9|T%q2O  
nM  D^x  
:W,6zv(..u  
InputStream input = httpConnection.getInputStream(); M#on-[  
//logResponseHead(httpConnection); {*H&NI  
Pze$QBNoRd  
^Sx 0t  
byte[] b = new byte[1024]; CU 2;m\Hc  
int nRead; %'j)~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6\)61o_1|  
{ zF%CFqQ  
nStartPos += fileAccessI.write(b,0,nRead); c&2ZjM  
//if(nThreadID == 1) / Dj6Bj }  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T[s_w-<7$  
} @(PYeXdV6&  
^jb55X}  
7/NXb  
Utility.log("Thread " + nThreadID + " is over!"); [P2$[|IM  
bDownOver = true; Lm\N`  
//nPos = fileAccessI.write (b,0,nRead);  W-@A  
} T%K(opISc(  
catch(Exception e){e.printStackTrace ();} XJsHy_6  
} i$)bZr\  
} =,KRZqz  
&TE=$a:d&  
9 )u*IGj  
//打印回应的头信息 7*y_~H  
public void logResponseHead(HttpURLConnection con) J&S$F:HM  
{ O>xGH0H  
for(int i=1;;i++) .&.j?kb  
{ =6imrRaaV  
String header=con.getHeaderFieldKey(i); $x 6Rmd{  
if(header!=null) [o<R#f`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /j./  
Utility.log(header+" : "+con.getHeaderField(header)); :kqJ~  
else Dna0M0   
break; $"C]y$}  
} 0 V*Di2  
} r#*kx#"  
oabc=N!7r  
R9D< lX0%  
public void splitterStop() JPS22i)P  
{ q5?g/-_0[  
bStop = true; %TdZ_  
} MVz=:2)J2  
MhNzmI&`  
ws Lg6  
} U .hV1  
NY\q  
<Bb $d@c  
/* V(1Ldl'a  
**FileAccess.java U 9TEC)  
*//文件访问(定位,写) Lv+lLK  
package NetFox; BKfcK>%g  
import java.io.*; |E0>-\6  
gxpR#/(E~  
r]Bwp i%  
public class FileAccessI implements Serializable{ _KC)f'Cx  
eX7Ev'(H  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jI(~\`  
RandomAccessFile oSavedFile; r9 'lFj  
long nPos; < i"U%Ds(  
V"(S<o  
$q]((@i.  
public FileAccessI() throws IOException {M U>5\  
{ .2/(G{}U  
this("",0); : m$cnq~h  
} X|t?{.p  
h<\o[n7j  
A:ls'MkZ4  
public FileAccessI(String sName,long nPos) throws IOException `o yz"07m  
{ aM5zYj`pW  
oSavedFile = new RandomAccessFile(sName,"rw"); ~PP*k QZlJ  
this.nPos = nPos; T{d7,.:  
oSavedFile.seek(nPos); $-YS\R\9x  
} +Sv`23G@  
!OekN,6  
TAl py$  
public synchronized int write(byte[] b,int nStart,int nLen) &K2[>5 mG  
{ } WY7!Y  
int n = -1; #K'3` dpL  
try{ p>h B&h  
oSavedFile.write(b,nStart,nLen); 2<)63[YO  
n = nLen; Fh9`8  
} .,(bDXl?  
catch(IOException e) e4u$+  
{ qCOv4b`  
e.printStackTrace (); >/nS<y>  
} VS@o_fUx)  
kX."|]  
E8J `7sa  
return n; "12.Bi.O"[  
} @4Z>;  
$Ll]h</Z  
e5maZ(.;F  
} ,,S5 8\x  
'W usEME  
sh[Yu  
/* \Xc6K!HJM  
**SiteInfoBean.java FYR%>Em  
*/ ~{iBm"4  
package NetFox; EMzJJe{Cv  
p8hF`D~  
%YG ~ql  
public class SiteInfoBean { eG9tn{  
]S<eO6z  
[5,aBf) X  
private String sSiteURL; //Site's URL > xkl7D  
private String sFilePath; //Saved File's Path ^%-$8sV  
private String sFileName; //Saved File's Name 5t#+UR  
private int nSplitter; //Count of Splited Downloading File su/l'p'  
)Y}t~ Zfx  
Gp'rN}i^  
public SiteInfoBean() :,%~rR  
{//nSplitter的缺省值为5 st P~/}  
//default value of nSplitter is 5 csz/[*  
this("","","",5); HGfV2FtTz  
} >'wl)j$  
eWS[|' dl  
KhAj`vOzK  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J?Brnf.  
{ /c'3I  
sSiteURL= sURL; 7)!(0.&  
sFilePath = sPath; h2ewYe<87`  
sFileName = sName; Z0g3> iItM  
this.nSplitter = nSpiltter; ]N_(M   
f1(V~{N,+  
c<L^ 1,G2  
} v~e@:7d i  
j*n Z   
8PB(<|}u  
public String getSSiteURL() _'0HkT{I  
{ r-v ;A  
return sSiteURL; >J^bs &j  
} 0?  (  
WM5 s  
Wk"4mq  
public void setSSiteURL(String value) V|KYkEl r1  
{ '; ,DgR;'  
sSiteURL = value; ne] |\]  
} n3t1'_/TU}  
h 1G`z  
$'*@g1v Y  
public String getSFilePath() i<&*f}='  
{ iM+K&\{_h  
return sFilePath; fu'iG7U M  
} %l%5Q;t  
Y,?s-AB  
Ks . m5R  
public void setSFilePath(String value) u"XqWLTV  
{ xr+K: bw  
sFilePath = value; |F[E h ~  
} Vd~{SS 2>  
Hq[d!qc  
]J+ }WR  
public String getSFileName() YMOy 6C  
{ #-dfG.*  
return sFileName; #\KSv Z  
} Q*}#?g  
P1)f-:;  
EKoAIC*?p  
public void setSFileName(String value) ac"Pn? q  
{ VXXo\LQUU  
sFileName = value; pV{MW#e  
} %5 V!Fdb  
['ol]ZJ  
Wm$( b2t  
public int getNSplitter() N|K,{ p^li  
{ Q1J./C}  
return nSplitter; eWzD'3h^  
} H7n5k,  
eKi/Mt  
Fj}|uiOQUS  
public void setNSplitter(int nCount) i*B@#;;F  
{ r2H \B,_  
nSplitter = nCount; &SfJwdG*=  
} {$z)7s  
} < .&t'W  
:W(3<D7\  
2-5AKm@K  
/* fH~InDT^  
**Utility.java 3&'ll51t  
*/ l G12Su/  
package NetFox; 7|LJwXQ-  
qa wb9Iud0  
T- ID{i  
public class Utility { ^_ <jg0V  
qYv/" 1  
*5Upb,* *  
public Utility() x'kwk  
{ N p9N#m?  
>FED*C4  
?#?[6t  
} ks|[`FH  
J.Mj76\_  
//线程睡眠 834(kw+#9  
public static void sleep(int nSecond) T)wc{C9w  
{ m<)0 XE6w  
try{ Z&FC:4!!  
Thread.sleep(nSecond); ( ,1}P  
} b:3n)-V{u  
catch(Exception e) 08AC 9  
{ {Ts@#V=:  
e.printStackTrace (); N<o3pX2i]  
} hFl$u8KV  
} U]j4Izq  
su6x okt  
//日志 f"t\-ux.b  
public static void log(String sMsg) {o"X8  
{ IPmSkK  
System.err.println(sMsg); C{>@b:]p  
} It'hmwu#  
nB"r<?n<  
]jiM  
public static void log(int sMsg) jqxeON  
{ nM:e<`r  
System.err.println(sMsg); p'UYH t  
} {N1Ss|6  
} wuE]ju<  
fy04/_,q  
,ButNB v  
/* e^kccz2f  
**TestMethod.java 4DI.R K9  
*/ RG/M-  
package NetFox; <,p|3p3  
*O-1zIlp  
bOjvrg;Sz\  
public class TestMethod { Poy ]5:.  
o`S|  
UwOZBF<  
public TestMethod() .,zrr&Po  
{ ///xx/weblogic60b2_win.exe yoa"21E$  
try{ xLX<. z!r  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 58\rl G  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *(6vO{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wY|&qX,  
fileFetch.start(); W^; wr#  
} -=BQVJ_dK{  
catch(Exception e){e.printStackTrace ();} .Tr!/mf_  
]oB-qfbH  
5=%:CN!/@p  
} hJY= )  
ceBu i8a |  
/Am,5X.   
public static void main(String[] args) `|K30hRp:  
{ 9bvzt8pc  
new TestMethod(); #<d f!)  
} {^>dQ+Sx7  
} C9zQ{G  
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