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http断点续传简单实现(java)

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/* #NSaY+V  
**SiteFileFetch.java '$lw[1  
*/ d9ZDpzx B  
package NetFox; 7=AO^:=bx  
import java.io.*; 9n-RXVL+  
import java.net.*; <`^>bv9  
)vxVg*.Ee  
30e(4@!4vW  
public class SiteFileFetch extends Thread { s; ~J2h[  
!Q\X)C  
ye9QTK6$,  
SiteInfoBean siteInfoBean = null; //文件信息Bean A/ r;;S)%2  
long[] nStartPos; //开始位置 F&-5&'6G+  
long[] nEndPos; //结束位置 gDgP;i d  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 CA'hvXb.  
long nFileLength; //文件长度 P2s^=J0@  
boolean bFirst = true; //是否第一次取文件 `7+tPbjs  
boolean bStop = false; //停止标志 K1CMLX]m  
File tmpFile; //文件下载的临时信息 ^?JEyY  
DataOutputStream output; //输出到文件的输出流 \=TWYj_Ah  
oo"JMD)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) us(sZG  
public SiteFileFetch(SiteInfoBean bean) throws IOException kemr@_  
{ N}e(.  
siteInfoBean = bean; <PH3gyC  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));  W\zL  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9p!dQx  
if(tmpFile.exists ()) ?d,acm  
{ =W97|BIW,  
bFirst = false; uBV^nUjS"m  
read_nPos(); KX&Od@cQ$  
} -uS7~Ww.a  
else e{d_p%(  
{ % DHP  
nStartPos = new long[bean.getNSplitter()]; $Ykp8u,(  
nEndPos = new long[bean.getNSplitter()]; D<$j`r  
} +K @J*W 1  
E}E7VQjM  
u^;sx/  
%6vMpB`g  
} EC:x  ,i  
sP=2NqU3Q  
BUboP?#%)  
public void run() AF07KA#  
{ Qt)7mf  
//获得文件长度 t~udfOvY  
//分割文件 H znI R  
//实例FileSplitterFetch qugPs(uQ  
//启动FileSplitterFetch线程 -b Ipmp?  
//等待子线程返回 f^>lObvd  
try{ ^[SbV^DOL  
if(bFirst) gw*yIZ@3)  
{ =!Baz&#}  
nFileLength = getFileSize(); gs)%.k[BqG  
if(nFileLength == -1) 1yY'hb,0  
{ jtlDSf#  
System.err.println("File Length is not known!"); fNmG`Ke  
} %K/G+  
else if(nFileLength == -2) 0VWCm( f-  
{ C=pPI  
System.err.println("File is not access!"); ^.B `Z{Jb  
} ()rx>?x5  
else J_)z:`[yE  
{ ! S$oaCxM  
for(int i=0;i<nStartPos.length;i++) Ve')LY<  
{ 9X*eE  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); P"[l86:  
} ) J:'5hz  
for(int i=0;i<nEndPos.length-1;i++) Uzm[e%/`  
{ )x5$io   
nEndPos = nStartPos[i+1]; "m\UqQGX  
} lMI ix0sSj  
nEndPos[nEndPos.length-1] = nFileLength; d(dw]6I6  
} B "s8i{Vm  
} @[Jt~v  
u"CIPc{Sr  
1&>nL`E[3  
//启动子线程 ~6Ee=NaLzP  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S]e~)I gO  
for(int i=0;i<nStartPos.length;i++) +A&IxsTq5=  
{ Rqd%#v  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +{ ,w#@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S'H0nJ3  
nStartPos,nEndPos,i); c Gaz$=/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _|Kv~\G!  
fileSplitterFetch.start(); 'AlSq:gZ  
} .w*{=x0k  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oW\7q{l2)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;zxlwdfcr'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E.Gh@i  
nEndPos = " + nFileLength); eG2qOq$[  
// fileSplitterFetch[nPos.length-1].start(); >8{`q!=|~  
XiZ Zo  
2+G:04eS,e  
//等待子线程结束 He$mu=$q{  
//int count = 0; R'a5,zEo/  
//是否结束while循环 F.* snF  
boolean breakWhile = false; (J) Rs`_  
ezNE9g  
,:Ix s^-  
while(!bStop) Cg%I)nz  
{  PtVNG  
write_nPos(); /Vj byRwV  
Utility.sleep(500); )Q pP1[  
breakWhile = true; :Y)kKq d  
PezWc18  
c 6}xnH  
for(int i=0;i<nStartPos.length;i++) "T=3mv%S  
{ |@n{tog+-  
if(!fileSplitterFetch.bDownOver) :J)l C =  
{ ch2e#Jf8  
breakWhile = false; (nP*  
break; J\8l%4q3  
} N<i Vs  
} VRN9yn2  
if(breakWhile) /dP8F  
break; |LGNoP}SA  
zR/p}Wu|!  
h ?qYy$  
//count++; U8I~co:h  
//if(count>4) aPP<W|Cmo2  
// siteStop(); 2g07wJ6x  
} laRKt"A  
-gX2{dW  
g>oYEFFJ  
System.err.println("文件下载结束!"); `8 b6 /  
} =)UiI3xHk  
catch(Exception e){e.printStackTrace ();} 01d26`G$i~  
} D;8V{Hs  
_ JJ0pc9t  
fkUH]CdaB  
//获得文件长度 nQYS{`hk  
public long getFileSize() v'~nABYH  
{ :phD?\!w8t  
int nFileLength = -1; %a6]gsiv2<  
try{ 9P >S[=  
URL url = new URL(siteInfoBean.getSSiteURL()); OL9C #er  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =$z$VbBv  
httpConnection.setRequestProperty("User-Agent","NetFox"); hO@v\@;r  
wyhf:!-I  
S2GBX1  
int responseCode=httpConnection.getResponseCode(); ?g*T3S"  
if(responseCode>=400) HyYQQ  
{ i3WmD@  
processErrorCode(responseCode); jW0z|jr  
return -2; //-2 represent access is error =}o>_+"  
} \ A UtGP  
c\rbLr}l)  
5pyvs;As  
String sHeader; <T% hfW  
<`p'6n79  
7[<sl35  
for(int i=1;;i++) &,kB7r"  
{ I;4CvoT  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }AfPBfgC1z  
//Utility.log(in.readLine()); #CP, \G  
sHeader=httpConnection.getHeaderFieldKey(i); \gQ+@O&+  
if(sHeader!=null) _89G2)U=C  
{ fQA)r  
if(sHeader.equals("Content-Length")) umrI4.1c  
{ 2o5< nGn  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?4?jG3p  
break; Mz. &d:  
} fJ lN'F7  
} >!p K94  
else &!~n=]*sz  
break; `.-k%2?/  
} m@2xC,@  
} Bw7:ry  
catch(IOException e){e.printStackTrace ();} %((3'le  
catch(Exception e){e.printStackTrace ();} K}(n;6\  
F"P:9`/  
'\YhRU  
Utility.log(nFileLength); $i] M6<Vxn  
G[-jZ  
f?^xh  
return nFileLength; VCtiZ4  
} tf79Gb>  
fw};.M  
*B}R4Y|g  
//保存下载信息(文件指针位置) SF=|++b1f  
private void write_nPos() Y6DiISl  
{ E1v<-UPbA  
try{ =w?cp}HW  
output = new DataOutputStream(new FileOutputStream(tmpFile)); g]Ny?61  
output.writeInt(nStartPos.length); 3VB V_/i;  
for(int i=0;i<nStartPos.length;i++) H#` ?toS  
{ O5*uL{pvT{  
// output.writeLong(nPos); =YsTF T  
output.writeLong(fileSplitterFetch.nStartPos); HON[{Oq  
output.writeLong(fileSplitterFetch.nEndPos); 54j $A  
} 6oBt<r?CJ  
output.close(); <aD+Ki6  
} `7n,(  
catch(IOException e){e.printStackTrace ();} .Vjpkt:H  
catch(Exception e){e.printStackTrace ();} gbZX'D  
} M8Lj*JN  
P[oB'  
CfnCi_=[`  
//读取保存的下载信息(文件指针位置) ne*aC_)bT  
private void read_nPos() O5%F-}(:  
{ oh~Dbu=%  
try{ X0=- {<W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XArLL5_L  
int nCount = input.readInt(); G ~\$Oq8  
nStartPos = new long[nCount]; bFXCaD!{G  
nEndPos = new long[nCount]; 41D[[Gh  
for(int i=0;i<nStartPos.length;i++) nu -wQr  
{ HJrg  
nStartPos = input.readLong(); Om{ML,d  
nEndPos = input.readLong(); ;BvWU\!  
} =S +:qk  
input.close(); Jev.o]|_,  
} R:<AR.)K  
catch(IOException e){e.printStackTrace ();} z<=t3dj  
catch(Exception e){e.printStackTrace ();} 1S#bV} !  
} u8=|{)yL  
4"=pcHNV  
I2Q?7p  
private void processErrorCode(int nErrorCode) zwHsdB=v  
{ g8y Zc}4  
System.err.println("Error Code : " + nErrorCode); \MPy"uC  
} Ms3/P|{"p  
YI+|6s[  
7w({ GZ  
//停止文件下载 (<-0UR]%q;  
public void siteStop() fE}}>  
{ _RVXE  
bStop = true; h UDEjW@S  
for(int i=0;i<nStartPos.length;i++) 014!~c  
fileSplitterFetch.splitterStop(); %"V,V3kw4  
%hQ`b$07t  
z05pVe/5  
} dGN*K}5  
} @) wXP@7  
//负责部分文件的抓取 c+VUk*c3  
**FileSplitterFetch.java qQryv_QP  
*/ Jy$-)  
package NetFox; 5=e@yIr'#  
c6.|; 4  
<C(2(3  
import java.io.*; ,)8Hl[y  
import java.net.*; >MLqOUr#  
=!aV?kNS8  
8a1{x(\z.  
public class FileSplitterFetch extends Thread { 1's^W  
i^Q^F  
KDk^)zv%!  
String sURL; //File URL 9m>_q Wa A  
long nStartPos; //File Snippet Start Position C ^'}{K  
long nEndPos; //File Snippet End Position 3]A'C&  
int nThreadID; //Thread's ID KxI(# }5o&  
boolean bDownOver = false; //Downing is over wu3ZSLY  
boolean bStop = false; //Stop identical |H49 FL  
FileAccessI fileAccessI = null; //File Access interface $TiAJ}:  
,P]{*uqGiB  
u)ItML  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 57rP@,vj  
{ *{Vyt5  
this.sURL = sURL; C_o.d~xm  
this.nStartPos = nStart; HH+XEMP/g  
this.nEndPos = nEnd; {Gy_QRsp,  
nThreadID = id; 1l{n`gR  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +`xp+Q  
} DzMkeX  
Zf! 7pM  
H>?@nYP  
public void run() .7q#{`K^=  
{ L;;x%>  
while(nStartPos < nEndPos && !bStop) &0myA_So  
{ e %#f9i  
Rp1OC  
<KCgtO  
try{ e5Z\v0  
URL url = new URL(sURL); =W?c1EPLCx  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;#*mB`  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Uh}|6PU  
String sProperty = "bytes="+nStartPos+"-"; <@P0sd   
httpConnection.setRequestProperty("RANGE",sProperty); 0td;Ag  
Utility.log(sProperty); Q{l;8MCL  
<=lP6B  
!G37K8 &&*  
InputStream input = httpConnection.getInputStream(); gKnAw+u\  
//logResponseHead(httpConnection); OpfFF;"A'  
YN^8s  
j"]%6RwM]  
byte[] b = new byte[1024]; t+ @F"[j  
int nRead; 0Pe.G0 #  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H}X"yLog*  
{ HD|5:fAqA  
nStartPos += fileAccessI.write(b,0,nRead); :Wln$L$  
//if(nThreadID == 1) =KMck=#B  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .(krB% N  
} <qu\q \  
UqH7ec  
LcXrD+ 1  
Utility.log("Thread " + nThreadID + " is over!"); $%<gp@Gz  
bDownOver = true; H!N,PI?rn  
//nPos = fileAccessI.write (b,0,nRead); a fjC~}  
} x!J L9  
catch(Exception e){e.printStackTrace ();} =e63>*M|  
} F+X3CB,f  
} QJ QQ-  
a^N/N5-Z  
[Z1EjeX  
//打印回应的头信息 t{ 'QMX  
public void logResponseHead(HttpURLConnection con) a v/=x  
{ ie)Qsw@  
for(int i=1;;i++) 1FuChd  
{ CBc}N(9  
String header=con.getHeaderFieldKey(i); 8w$cj'  
if(header!=null) z&eJ?wb  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jU=)4nx  
Utility.log(header+" : "+con.getHeaderField(header)); drH!?0Dpg  
else }I]9I _S  
break; ][.1b@)qV  
} 3Xy>kG}  
} @{j-B IRZ0  
?r/7:  
RGcT  
public void splitterStop() Q x:+n`$/  
{ XHW{EVcF  
bStop = true; z-,'W`  
} ' Mg%G(3  
)K}b,X`($  
'lWNU   
} 0GB6.Ggft  
$*tuv ?  
BD#4=u  
/* "l!"gc87  
**FileAccess.java pz(clTOD:  
*//文件访问(定位,写) 0X@5W$x  
package NetFox; F"LT\7yjyG  
import java.io.*; `ul"D%  
8`*(lKiL  
4;_.|!LN  
public class FileAccessI implements Serializable{ Q)v8hNyUmA  
sQR;!-j  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ] O 2_&cs  
RandomAccessFile oSavedFile; T_r[#j  
long nPos; *rWE.4=&  
0KEytm]  
q.#aeqKBP  
public FileAccessI() throws IOException ,L`qV  
{ L&eO?I=,  
this("",0); n^'{{@&(v  
} H94$Xi"Bd  
9[:nW p^  
/wmJMX  
public FileAccessI(String sName,long nPos) throws IOException 9t=erhUr  
{ kG%<5QH  
oSavedFile = new RandomAccessFile(sName,"rw"); 4*'NpqC(_  
this.nPos = nPos; H~ (I  
oSavedFile.seek(nPos); " <=^Sm  
} bju0l[;=  
S6cSeRmw  
I@.qon2V  
public synchronized int write(byte[] b,int nStart,int nLen) KExfa4W 3{  
{ &%^[2^H8"  
int n = -1; z8A`BVqI  
try{ 6~^+</?  
oSavedFile.write(b,nStart,nLen); 7%JXVP}A  
n = nLen; W0R6<- 1  
} Y~Zg^x2  
catch(IOException e) lVMAab  
{ B} &C h  
e.printStackTrace (); h$lY,7  
} \2 W( >_z  
T `N(=T^*  
Xa-]+_?Q  
return n; )U8F6GIC&}  
} |]Ockg[  
vh T9#) HI  
4iDo.1B"  
} !zD| @sX{  
GlVq<RG*  
`,TPd ~#~  
/* 0ro)e~_@*  
**SiteInfoBean.java 3fpX  
*/ GJ!usv u  
package NetFox; G.L4l|%W  
{ Ke3  
i^j{l_-JE  
public class SiteInfoBean { W&G DE  
x'}{^'}/  
d d8^V_Kx  
private String sSiteURL; //Site's URL 5C/u`{4]Hg  
private String sFilePath; //Saved File's Path >4bOM@[]  
private String sFileName; //Saved File's Name ZSxKk6n}J  
private int nSplitter; //Count of Splited Downloading File W C}mt%H*O  
n_iq85  
x}72jJe`  
public SiteInfoBean() t,+p!"MRY  
{//nSplitter的缺省值为5 NH4EsV]  
//default value of nSplitter is 5 J\#6U|a""u  
this("","","",5); jt?R a1Z  
} z^ ~fVl  
 Zuwd(q  
BC&Et62*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g~N)~]0{  
{ ~KEnZa0  
sSiteURL= sURL; U edh4qa  
sFilePath = sPath; D,]m7 yFT  
sFileName = sName; &AA u:  
this.nSplitter = nSpiltter; MiN68x9  
Ro?yCy:L'  
0p! [&O  
} IgZX,4i=o  
|qfnbi-\  
D`iWf3a.  
public String getSSiteURL() L[<MBgF Kv  
{ SrU,-mA W  
return sSiteURL; OpYq qBf_  
} 2uV=kqnO  
:y 0'[LV  
iQ~cG[6  
public void setSSiteURL(String value) DtyT8kr  
{ hnL(~  
sSiteURL = value; % kKtPrT  
} jUdW o}/  
& 9IMZAo  
BYP,}yzA  
public String getSFilePath() !dGy"-i$h  
{ 1 BVivEG  
return sFilePath; ;z!~-ByzL  
} 2x'JR yef  
to+jQ9q8  
0G;RMR':5  
public void setSFilePath(String value) ai#0ZgO  
{ ^h=;]vxO  
sFilePath = value;  6 5qH  
} v='7.A  
eRC@b^~  
mi i9eZ  
public String getSFileName() IN),Lu0K  
{ {U7j  
return sFileName; X2Y-TE T  
} amgYr$)m  
NcRY Ch  
6SW:'u|90  
public void setSFileName(String value) SbrBlP: G  
{ liPUK#  
sFileName = value; ^hTq~"  
} YgrBIul  
'^}l|(  
Ch^Al 2)=  
public int getNSplitter() G,$RsP  
{ %;9wToyK>  
return nSplitter; |\Jpjm)?  
} 2~~Q NWN  
z&9vKF  
w9l)=[s=  
public void setNSplitter(int nCount) ?zKDPBj  
{ *}cF]8c5W  
nSplitter = nCount; m3K8hL/  
} n+j'FfSz  
} 7J7uHl`yq`  
Q{V|{yV^y  
T<?JL.8g_  
/* (N0G[(>  
**Utility.java *}A J7]  
*/ |_ E)2b:h  
package NetFox; !&ac}uD^g  
.u)Po;e`  
pgfI1`h  
public class Utility { tb^3-ZUb  
XEY((VL0  
zEpcJHI%  
public Utility() 9kQ~)4#  
{  ,`)!K}2  
Sh}AGNE'  
GYyP+7K4l[  
} r4D6g>)h1q  
l^WFMeMD3a  
//线程睡眠 , B h[jb`y  
public static void sleep(int nSecond) )# M*@e$k  
{ Ga"$_DyM  
try{ 5}E8Tl  
Thread.sleep(nSecond); HmAA?J}  
} mS0*%[S {  
catch(Exception e) ?UQE;0 B  
{ ,d@.@a] `  
e.printStackTrace (); >/eQjp?:  
} @ 4j#X  
} {pm>F}Cwy  
]7fqVOiOu  
//日志 J'.U+XU  
public static void log(String sMsg) S_ e }>-  
{ V<?t( _Y  
System.err.println(sMsg); sq\oatMw[  
} LKFL2|af  
x$?{)EY  
 J$v0  
public static void log(int sMsg) wYOSaGyZ0I  
{ [D^KM|I%+  
System.err.println(sMsg); (KK9/k  
} 7P.C~,+D%P  
} YSs9BF:a  
l X;2~iW{/  
Nq"/:3@4  
/* xW#r)aN]p  
**TestMethod.java 2_R' Kl![  
*/ N?ky2wG  
package NetFox; 8 U B?X  
wBA[L}  
m+s^K{k}  
public class TestMethod { CT6a  
Lg sQz(-  
}pTy mAN  
public TestMethod() *U)!9DvA  
{ ///xx/weblogic60b2_win.exe h7wm xa;  
try{ v;80RjPy>  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /~K-0K#w  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $7T3wv9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); A|O7W|"W  
fileFetch.start(); x{6/di  
} }2|>Y[v2j  
catch(Exception e){e.printStackTrace ();} rH8w||S2U  
hmHm;l  
!dv  
} CY <,p$  
o>';-} E  
2$jTj<.K  
public static void main(String[] args) w q% 4'(  
{ >u4%s7 v  
new TestMethod(); CVyqr_n65/  
} +>@<'YI<  
} E dhT;!  
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