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http断点续传简单实现(java)

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/* QKEtV  
**SiteFileFetch.java FZ%h7Oe  
*/ 7bbFUUUG"  
package NetFox; HCrQ+r{g  
import java.io.*; 9;I%Dv  
import java.net.*; ._>03,"  
.7 )oWd!  
@D*PO-s9  
public class SiteFileFetch extends Thread { ud(0}[  
pam9wfP  
 |15!D  
SiteInfoBean siteInfoBean = null; //文件信息Bean I74Rw*fB  
long[] nStartPos; //开始位置 h{_\ok C>  
long[] nEndPos; //结束位置 ^ )"Il  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 CG@Fn\J  
long nFileLength; //文件长度 ,]yS BAO  
boolean bFirst = true; //是否第一次取文件 \"RCJadK  
boolean bStop = false; //停止标志 XXX y*/P  
File tmpFile; //文件下载的临时信息 ^HR8.9^[1u  
DataOutputStream output; //输出到文件的输出流 M]k Q{(  
&+(D< U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) %{IgY{X  
public SiteFileFetch(SiteInfoBean bean) throws IOException # "c'eG0  
{ 6ERMn"[_w  
siteInfoBean = bean; #wT6IU1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); xx1lEcj  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &QD)1b[U  
if(tmpFile.exists ()) Z~h6^h   
{ 2!}F+^8'P  
bFirst = false; 3 eF c  
read_nPos(); Hmm0H6&u  
} 'MX|=K!C  
else 0+qC_ISns  
{ o:cTc:l)  
nStartPos = new long[bean.getNSplitter()]; ^/}4M'[w  
nEndPos = new long[bean.getNSplitter()]; cy(w*5Upu  
} {T^D&i# o  
KyT=:f V  
zd8A8]&-  
a;KdkykG  
} |S).,B  
XZ8rM4 ]  
6 %aaK|0  
public void run() B*}]'  
{ `WCL-OoZc5  
//获得文件长度 l=T;hk  
//分割文件 6W1+@ q  
//实例FileSplitterFetch aY,Bt  
//启动FileSplitterFetch线程 qHgtd+ I  
//等待子线程返回 4qE4 i:b  
try{ kmTYRl )j  
if(bFirst) i)(G0/:  
{ 2DsP "q79k  
nFileLength = getFileSize(); ?5ZvvAi  
if(nFileLength == -1) gQSVPbzK  
{ aB (pdW4  
System.err.println("File Length is not known!"); uUx7>algF  
} >G"fMOOkW  
else if(nFileLength == -2) EpRn,[  
{ QPLWRZu@  
System.err.println("File is not access!"); h]~FYY  
} aqqo>O3 s  
else re%XaL  
{ Hicd -'  
for(int i=0;i<nStartPos.length;i++) ;Q q_  
{ 6RxI9{ry  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); CeOA_M  
} Go:(R {P  
for(int i=0;i<nEndPos.length-1;i++) !nJl.Y$  
{ 3)CIqN  
nEndPos = nStartPos[i+1]; ayn aV  
} 2/t;}pw8  
nEndPos[nEndPos.length-1] = nFileLength; j>\rs|^O  
} \hI?XnL#  
} 'xai5X  
6J JA"] `  
S}h d,"I  
//启动子线程 Z R=[@Oi  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2uT6M%OC  
for(int i=0;i<nStartPos.length;i++) ]smu~t0\  
{ :, v(l q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v,Z]Vqk  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ot56`,k  
nStartPos,nEndPos,i); .eVX/6,  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gn/]1NNfR  
fileSplitterFetch.start(); ?&,6Y'"  
} SfPQ;s'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3k>#z%//  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !wd wo0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wDoCc:  
nEndPos = " + nFileLength);  (t5y$b c  
// fileSplitterFetch[nPos.length-1].start(); }yrs6pQ  
zb[kRo&a0W  
g%]<sRl:-  
//等待子线程结束 PCgr`($U  
//int count = 0; ]Z\W%'q+  
//是否结束while循环 l}-k>fug  
boolean breakWhile = false; ziO(`"v  
[cEGkz  
(JdheCq!x  
while(!bStop) Mi(6HMA.SF  
{ @VOegf+N  
write_nPos(); ^J^~5q8  
Utility.sleep(500); ?xMTO  
breakWhile = true; !.V_?aYi8  
gU&+^e >  
2<n 18-|OQ  
for(int i=0;i<nStartPos.length;i++) ^)Y3V-@t  
{ &Q"vXs6Gt  
if(!fileSplitterFetch.bDownOver)  Br s}  
{ bvZD@F`2  
breakWhile = false; Zp_j\B  
break; "#0P*3-c  
} RWM~7^JA  
} p}!)4EI=  
if(breakWhile) 5z3WRg  
break; 3HP { a  
_a"| :kX  
6K8v:yYPa  
//count++; 6?US<<MQ  
//if(count>4) mP15PZ  
// siteStop(); $(0<T<\  
} n;xzjq-  
)q4nyT>M  
>a2[P"   
System.err.println("文件下载结束!"); .^F&6'h1H  
} U{l f$  
catch(Exception e){e.printStackTrace ();} I;_T_m4.q  
} >#mKM%T2MJ  
RYC%;h  
ZT/f  
//获得文件长度 |mWSS'7fI  
public long getFileSize() j+AZ!$E  
{ W6EEC<$JL  
int nFileLength = -1; twldwuN  
try{ " @ ""  
URL url = new URL(siteInfoBean.getSSiteURL()); ^qC.bv]&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 75R4[C6T  
httpConnection.setRequestProperty("User-Agent","NetFox"); og+Vrd  
mGP%"R2X  
h \`(  
int responseCode=httpConnection.getResponseCode(); O\yYCi(  
if(responseCode>=400) 6z~ [Ay  
{ 3 Z SU^v  
processErrorCode(responseCode); }*-fh$QJ  
return -2; //-2 represent access is error RmKbnS $*q  
} Z9% u,Cb  
Pk5\v0vkg  
:Zq?V`+M  
String sHeader; 5)k/ 4l '  
L!/{Z  
[.$%ti*!  
for(int i=1;;i++) {#z47Rz  
{ ]+qd|}^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g_tEUaiK  
//Utility.log(in.readLine()); p'@z}T?F  
sHeader=httpConnection.getHeaderFieldKey(i); h;} fdk  
if(sHeader!=null) ZZ!6O/M  
{ 'i3-mZ/|8  
if(sHeader.equals("Content-Length")) O@H D'  
{ KU+u.J  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l&] %APL  
break; R"t2=3K  
} T72Z<h|<  
} Avljrds+7  
else 5c%Fb :BW=  
break; h= YTgJ  
} z:dW'U?1  
} J$jLGy&'  
catch(IOException e){e.printStackTrace ();} X&49C:jN  
catch(Exception e){e.printStackTrace ();} @{<^rLt  
5 8U[IGs(  
n~w[ajC/  
Utility.log(nFileLength); oM#+Z qP  
u,YmCEd_V  
~$ ?85   
return nFileLength; <Z~Nz>'r  
} | z}VP-L  
.bh 7  
2Z^p)  
//保存下载信息(文件指针位置) 8193d%Wb  
private void write_nPos() @1pfH\m  
{ yMgS0  
try{ \!>qtFT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ee Bw\f0  
output.writeInt(nStartPos.length); 6_9@s*=d>  
for(int i=0;i<nStartPos.length;i++) Dg ~k"Ice  
{ 3<a|_(K  
// output.writeLong(nPos); Esj1Vv#  
output.writeLong(fileSplitterFetch.nStartPos); ] TZ/=Id  
output.writeLong(fileSplitterFetch.nEndPos); 11A;z[Zk  
} G-o6~"J\  
output.close(); -"N vu  
} YB{'L +Wbw  
catch(IOException e){e.printStackTrace ();} h2+"e# _  
catch(Exception e){e.printStackTrace ();} KlwB oC/{K  
} U?:?NC=1{  
O6q5qA  
f.vJJa  
//读取保存的下载信息(文件指针位置) <\ ".6=E#W  
private void read_nPos() 7.yCs[Z  
{  ? EhIK  
try{ -3y $j+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _*t75e$-  
int nCount = input.readInt(); [A;0I jKam  
nStartPos = new long[nCount]; P!&yYR\  
nEndPos = new long[nCount]; e&<=+\ul  
for(int i=0;i<nStartPos.length;i++) @GQtyl;q  
{ b^P\Kky  
nStartPos = input.readLong(); Ob|tA  
nEndPos = input.readLong(); xCu\jc)2  
} ~!Rf5QA85  
input.close(); [XA:pj;rg'  
} vcOw`oS  
catch(IOException e){e.printStackTrace ();} \ tU[,3  
catch(Exception e){e.printStackTrace ();} ZzT"u1,&  
} ZZeF1y[q  
yW}x  
_tnoq;X[  
private void processErrorCode(int nErrorCode) /EVXkf0  
{ |[/XG2S  
System.err.println("Error Code : " + nErrorCode); |5BvVqn  
} clT[ ?8*  
'L%)B-,n  
c#fSt}J>C  
//停止文件下载 - l0X]&Ex  
public void siteStop() <Um5w1  
{ cw~-%%/  
bStop = true; Ige*tOv2  
for(int i=0;i<nStartPos.length;i++) RE;)#t?K  
fileSplitterFetch.splitterStop(); llpgi,-=  
r)dXcus  
T'14OU2N{Y  
} (6)X Fp&  
} "(;t`,F  
//负责部分文件的抓取 ;Z&w"oSJ  
**FileSplitterFetch.java 7C@m(oK  
*/ *.-qbwOg  
package NetFox; .`h:1FP 8  
+L=a\8Ep  
2 3A)^j  
import java.io.*; S <++eu  
import java.net.*; !!v9\R4um  
Q3LScpp  
`S]DHxS  
public class FileSplitterFetch extends Thread { 6?l|MU"Q.  
~:UAL}b{\~  
Rap_1o9#\  
String sURL; //File URL <'P+2(Oi  
long nStartPos; //File Snippet Start Position T FK#ign  
long nEndPos; //File Snippet End Position HhUk9 >7  
int nThreadID; //Thread's ID tHH @[E+h  
boolean bDownOver = false; //Downing is over t)l^$j !h@  
boolean bStop = false; //Stop identical chU,));F  
FileAccessI fileAccessI = null; //File Access interface arn7<w0  
o{MmW~/o&  
v<]$,V]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9 E  
{ | Fk9ME  
this.sURL = sURL; hJoh5DIE95  
this.nStartPos = nStart; 4~0 @(3  
this.nEndPos = nEnd; r 4+%9)  
nThreadID = id; TmgSV#G  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J/A UOInh  
} 6p~8(-nG  
.!g  
X0]5I0YP  
public void run() b5UIX Kim  
{ g;</|Z  
while(nStartPos < nEndPos && !bStop) lUM-~  
{ I oC}0C7  
/h K/t;  
iaQ3mk#  
try{ m/1;os5+8  
URL url = new URL(sURL); R-BN}ZS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x1 1ug  
httpConnection.setRequestProperty("User-Agent","NetFox"); !MD uj  
String sProperty = "bytes="+nStartPos+"-"; l|  QQ  
httpConnection.setRequestProperty("RANGE",sProperty); 20BU;D3  
Utility.log(sProperty); zWq&HBs  
BGL-lJrG  
\7tJ)[0aF  
InputStream input = httpConnection.getInputStream(); Jgzg[6  
//logResponseHead(httpConnection); h1QrFPQnu  
7j{63d`2  
gib;> nuBK  
byte[] b = new byte[1024]; ]iH~ 1[  
int nRead; jsIT{a*]  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SHUn<+/e  
{ jRSY`MU}t+  
nStartPos += fileAccessI.write(b,0,nRead); zFO#oW,D  
//if(nThreadID == 1) %`^{Hh`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sj%\lq  
} Xwk_QFv3  
M[5fNK&nD  
4mwAo  
Utility.log("Thread " + nThreadID + " is over!"); uBxs`'C  
bDownOver = true; P&9&/0r=_  
//nPos = fileAccessI.write (b,0,nRead); =_9grF-  
} 4*_.m9{  
catch(Exception e){e.printStackTrace ();} $or8z2d1  
} 5^GrG|~  
} qM0Df0$?x  
A&qZ:&(OM  
l=ZX9<3  
//打印回应的头信息 JReJlDu  
public void logResponseHead(HttpURLConnection con) } !RBH(m%  
{ 8H2A<&3i  
for(int i=1;;i++) a3E.rr;b  
{ }Uunlz<  
String header=con.getHeaderFieldKey(i); LE4P$%>H  
if(header!=null) tLe"i>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]MV=@T^8#  
Utility.log(header+" : "+con.getHeaderField(header)); A$XmO}+  
else 0z=^_Fb  
break; '645Fr[lg  
} DzG$\%G2R}  
} \kVi&X=q:  
R\n*O@E v3  
> R2o7~  
public void splitterStop() gjex;h  
{ 1A;f[Rze  
bStop = true; S"Mm_<A$@  
} y@u,Mv  
y>_*}>2,O  
Q%^!j_#  
} .V\: )\<|  
Tq!.M1{&  
s_Gf7uC  
/* ~ZZJ/Cu  
**FileAccess.java hYU4%"X  
*//文件访问(定位,写) Y|N.R(sAs&  
package NetFox; w2o5+G=  
import java.io.*; p& +w  
Tn(c%ytN  
zT"W(3  
public class FileAccessI implements Serializable{ PvqG5-L~W  
" )/febBS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y8%*S%yO  
RandomAccessFile oSavedFile; 0N4+6k|  
long nPos; m<| *  
y?yWM8  
@DA.$zn&  
public FileAccessI() throws IOException =/L;}m)7  
{ cuo'V*nWQ  
this("",0); ":,J<|Oy  
} ok<!/"RX$  
a;[=b p  
a<mM )[U  
public FileAccessI(String sName,long nPos) throws IOException \XT~5N6  
{ )0p7d:%mV  
oSavedFile = new RandomAccessFile(sName,"rw"); dSw%Qv*y  
this.nPos = nPos; QPT%CW61M  
oSavedFile.seek(nPos); *HXx;:  
} s2Hx ?~  
-|nHwSrCZ/  
[ nG@ 3n  
public synchronized int write(byte[] b,int nStart,int nLen) oV Hh  
{ \?rBtD(  
int n = -1; &WAJ;7f  
try{ 'r_NA!R  
oSavedFile.write(b,nStart,nLen); ]9/{  
n = nLen; 15tT%TC  
} $g+q;Y~i0  
catch(IOException e) ;Vh5nO  
{ |}^ BF%8V:  
e.printStackTrace (); e:kd0)9  
} Y<EdFzle  
_vgFcE~E@  
W2G@-`,  
return n; B gB]M3Il  
} z;d]=PT  
-P7JaH/Q  
25CO_  
} F9 q9BH  
F1UTj "<e  
#> @~3kGg  
/* &['cZ/bM  
**SiteInfoBean.java @Ap~Wok  
*/ [  bB   
package NetFox; l/F'W}  
B2DWSp-8*  
K\a=bA}DG  
public class SiteInfoBean { 8KhE`C9z  
^J{tOxO=l  
1pT-PO 3=  
private String sSiteURL; //Site's URL iF1E 5{dH  
private String sFilePath; //Saved File's Path "<5su5]  
private String sFileName; //Saved File's Name 60r4%> d  
private int nSplitter; //Count of Splited Downloading File > qhoGg  
zOzobd   
^ H )nQ  
public SiteInfoBean() re;^,  
{//nSplitter的缺省值为5 HHU0Nku@ho  
//default value of nSplitter is 5 Q1?09  
this("","","",5); x]%'^7#v)  
} KaGG4?=V  
\6z_ ;  
[[sfuJD  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rx>>0%e.  
{ EA+}Rf6}  
sSiteURL= sURL; slWO\AYiO  
sFilePath = sPath; rfVHPMD0  
sFileName = sName; P&0o~@`cL  
this.nSplitter = nSpiltter; ;Q&|-`NK  
Y4.t:Uzr  
~xSAR;8  
} ollk {N  
sq~9 l|F  
vOKWi:-U  
public String getSSiteURL() Ug1n4X3FKn  
{ lE@ V>%b  
return sSiteURL; d}`Z| ex  
} {j{H@rHuy  
a.O pxd  
p^uX{!  
public void setSSiteURL(String value) !uwZ%Ux z  
{ jR[3{ Reo  
sSiteURL = value; :s5wFumD  
} tUPdq0%t[  
>|S&@<  
(+^z9p7/!  
public String getSFilePath() C%l+<wpXO  
{ S[zX@3eZV  
return sFilePath; 9< $n'g  
} {+V]saYP  
eXdE?j  
i G%h-  
public void setSFilePath(String value) Cj6+zJ  
{ /\0 rRT  
sFilePath = value; WK<:(vu.  
} 6pCQP c*A  
tin5.N)"z  
|)vC^=N{+  
public String getSFileName() 2sryhS'(H  
{ iE;D_m.>`O  
return sFileName; !8 V  
} v.Y?<=E+<d  
 ~;#OQ[  
RMfKM! vE  
public void setSFileName(String value) :4V8Iz 71  
{ ".Q``d&X  
sFileName = value; bI_T\Eft  
} R rtr\ a  
yD-L:)@"  
qlJzXq{|`  
public int getNSplitter() 1K`7  
{ C =6.~&(  
return nSplitter; ..5rW0lr  
} (&)PlIi7  
8w Xnc%  
CC8)yO  
public void setNSplitter(int nCount) g]V_)}  
{ m@Vz42g~+  
nSplitter = nCount; T|o ]8z  
} ;;#_[Zl  
} nH=8I~jp  
R;]z/|8  
mz'r<v2Tc  
/* BM,]Wjfdj  
**Utility.java %]m/fo4b  
*/ \pVmSac,  
package NetFox; z{N~AaY  
-s zSA  
,L.*95 ,  
public class Utility { P~H?[ ;  
lI<Q=gd  
nbMxQOD k  
public Utility() ; m]KKB  
{ hN5?u:  
m 3 Y@p$i5  
fQkfU;5  
} t6+c"=P#  
]"2;x  
//线程睡眠 C2[* $ 1U  
public static void sleep(int nSecond) XDtMFig  
{ 1[g -f ,  
try{ @  gv^  
Thread.sleep(nSecond); WE*L=_zDS  
} YXi'^GU@  
catch(Exception e) UBm L:Qv  
{ +'ZJ]  
e.printStackTrace (); !'jZ !NFO  
} XjRk1 ~  
} Biva{'[m  
%lbDcEsf9  
//日志 A%[ BCY_  
public static void log(String sMsg) s.#%hPX{  
{ hp$/O4fD  
System.err.println(sMsg); WEnI[JGe  
} {PTB]D'  
L2,.af6+  
~v$1@DQ}  
public static void log(int sMsg) >]!8f?,  
{ cUH. ^_a  
System.err.println(sMsg); w1&\heSQ  
} ZR," w  
} q9h 3/uTv  
aWCZ1F  
M&v;#CV  
/* C+m%_6<  
**TestMethod.java zFba("E Z  
*/ %2;Nj; J$  
package NetFox; 2I|`j^  
c;13V(Djy  
]VkM)< +  
public class TestMethod { dKk#j@[n"  
(^@rr[. o7  
d:X@zUR*)  
public TestMethod() -91*VBrOd  
{ ///xx/weblogic60b2_win.exe yd|roG/  
try{ Km)VOX[ZZ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);   L* 0$x  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a7fFp 9l!  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @,:6wKMc  
fileFetch.start(); \`:nmFO(9  
} AbExJ~JV\g  
catch(Exception e){e.printStackTrace ();} @fc-[pv  
\}n\cUy-  
g!\H^d4  
} P2!+ZJ&  
28! ke  
"M !]t,?S  
public static void main(String[] args) f'oO/0lx  
{ N8E  
new TestMethod(); v:1DNR4  
} 3-PqUJT$   
} CiNOGSlDj  
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