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http断点续传简单实现(java)

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/* 4 !m'9  
**SiteFileFetch.java 6s>io%,:  
*/ -hq^';,  
package NetFox; wYLodMaYH  
import java.io.*; Ly z8DwZ  
import java.net.*; hiv {A9a?  
x.$cP  
hhz#I A6,  
public class SiteFileFetch extends Thread { ]$#9B-uB  
%`~+^{Wp  
dc0&*/`:  
SiteInfoBean siteInfoBean = null; //文件信息Bean o'Fyo4Qd  
long[] nStartPos; //开始位置 W.%p{wB |  
long[] nEndPos; //结束位置 X"9N<)C  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 *>2e4j]  
long nFileLength; //文件长度 x!7r7|iV  
boolean bFirst = true; //是否第一次取文件 OT(0~,.GJ  
boolean bStop = false; //停止标志 olr-oi`4C  
File tmpFile; //文件下载的临时信息 |!/+ T^u  
DataOutputStream output; //输出到文件的输出流 4>HaKJ-c#  
=M}tet }  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) \RtFF  
public SiteFileFetch(SiteInfoBean bean) throws IOException 'nq~1 >i  
{ 59p'U/|  
siteInfoBean = bean; 3t9CN )*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); U#bmMH  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); J{\(Y#|rHs  
if(tmpFile.exists ()) F|VKrH.  
{ _CTg")0o  
bFirst = false; ;nJ2i?"  
read_nPos(); R]o0V*n  
} 'Z:wEt!  
else cM CM>*X  
{ U|{4=[  
nStartPos = new long[bean.getNSplitter()]; 3)L#V .  
nEndPos = new long[bean.getNSplitter()]; &5.J y2hO]  
} G9V2(P  
Om;aE1sW  
wt;`_}g  
)v*k\:Hw  
} )q.ZzijG/  
w\UAKN60  
7&/1K%x9;  
public void run() 'rS\9T   
{ jKo9y  
//获得文件长度 XT*/aa-1'  
//分割文件 |z"$^|@d?  
//实例FileSplitterFetch ZHUW1:qs  
//启动FileSplitterFetch线程 x!vyjp  
//等待子线程返回 CE!cZZ  
try{ }Y|M+0   
if(bFirst) Aqz $WTHW+  
{ A.@wGy4  
nFileLength = getFileSize(); W}"tf L8  
if(nFileLength == -1) fI2 y(p{?  
{ S8+l!$7   
System.err.println("File Length is not known!"); Z!Z{Gm3  
} 8DMqjt3B  
else if(nFileLength == -2) N$v_z>6Z  
{ ixK9/5T  
System.err.println("File is not access!"); gm n b  
} B0A y  
else jUl_ToX  
{ |(TEG.<g  
for(int i=0;i<nStartPos.length;i++) `sIm&.d  
{ [i.c;'Wy/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); M(:bM1AD`u  
} It/hXND `  
for(int i=0;i<nEndPos.length-1;i++) xLLTp7b(  
{ K7.ayM 0  
nEndPos = nStartPos[i+1]; 0UW_ Pbh6  
} f Ayh9  
nEndPos[nEndPos.length-1] = nFileLength; n[r1h=?j3  
} PhV/WjCZ  
} w1(5,~OB  
BNA1"@9q  
@8w5Oudvx  
//启动子线程 1*$6u5.=F  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; | oM`  
for(int i=0;i<nStartPos.length;i++) =./PY10'  
{ (x@J@ GP*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P*>?/I`G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,quUGS  
nStartPos,nEndPos,i); /*BK6hc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1{]S[\F]  
fileSplitterFetch.start(); $%!06w#u  
} 0%;| B  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {q+gm1iC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PX0N7L  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n[qnrk*3 %  
nEndPos = " + nFileLength); ]N0B.e~D  
// fileSplitterFetch[nPos.length-1].start(); WlY\R>x#  
\6.dGKK  
\o3s&{+ y,  
//等待子线程结束 ?/5<}W#7}  
//int count = 0; C`3 XOth  
//是否结束while循环 Wd(|w8J{a  
boolean breakWhile = false; 'rFLG+W  
]]`[tVaFr  
Y*A y=@z=y  
while(!bStop) 23K#9!3  
{ =B'Yx  
write_nPos(); O'^AbO=,  
Utility.sleep(500); #nft{AN  
breakWhile = true; QhAYCw2  
dD'KP4Io@  
<;>k[P'  
for(int i=0;i<nStartPos.length;i++) D'{ o3Q,%K  
{ sAs`O@  
if(!fileSplitterFetch.bDownOver) EV* |\ te  
{ mr_NArF  
breakWhile = false; X|g5tnsj`  
break; J8@+)hn  
} |a /cw"  
} j5[ >HL  
if(breakWhile) f*hnzj  
break; ;Z;` BGZJ  
@n9iOf~<  
2v4&'C  
//count++; \>w 2D  
//if(count>4) RLLL=?W@  
// siteStop(); x 2l}$(7  
} JlE+CAny  
$(OL#>9Ly  
$gk=~p|  
System.err.println("文件下载结束!"); " ;8kKR  
} fHI@' '0  
catch(Exception e){e.printStackTrace ();} c^&:':Z%'  
} -%[6q  
xs "\c7pC  
(f#{<^gd  
//获得文件长度 *>o@EUArN  
public long getFileSize() ,s@S`KS0  
{  Bv%dy[I  
int nFileLength = -1; G"vEtNoV  
try{ cj[%.M5iBA  
URL url = new URL(siteInfoBean.getSSiteURL()); RzLeR%O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V|nJ%G\  
httpConnection.setRequestProperty("User-Agent","NetFox"); [E}pU8.t6  
pf=CP%L  
!+Sd%2o  
int responseCode=httpConnection.getResponseCode(); Fy_~~nI0  
if(responseCode>=400) 5hAs/i9_  
{ g^\>hjNX  
processErrorCode(responseCode); Z$)jPDSr  
return -2; //-2 represent access is error  Zzr  
} @XKVdtG  
U/rFH9e$  
gaL.5_1  
String sHeader; HNfd[#gV  
sNC~S%[  
bGB5]%v,  
for(int i=1;;i++) |X~vsM0  
{ E `%*lGu_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "fd'~e$S#  
//Utility.log(in.readLine()); <bBgevL+_K  
sHeader=httpConnection.getHeaderFieldKey(i); @Z9>E+udQ  
if(sHeader!=null) o-]8)G>~M  
{ Pj*"2 LBW#  
if(sHeader.equals("Content-Length")) r9^~I  
{ NX<Q}3cC  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S'AS,'EnY  
break; k jR-p=}  
} ^c>ROpic  
} X.ZY1vO  
else LO ,k'gg<  
break; BOW`{=  
} Y2y = P  
} H^w Inkf>  
catch(IOException e){e.printStackTrace ();} G\S_e7$ /  
catch(Exception e){e.printStackTrace ();} 95  X6V  
_,|N`BBqd  
A4VV y~sd  
Utility.log(nFileLength); YoRD9M~iG~  
&uu69)u  
",Fqpu&M  
return nFileLength; G%fNGQwT  
} ,6^V)F  
}F)eA1  
(k5d.E]CK  
//保存下载信息(文件指针位置) Tn\59 (  
private void write_nPos() }kb6;4>c  
{ o7s<G8;?  
try{ o_%gFV[q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fhQ}Z%$  
output.writeInt(nStartPos.length); ^Jn=a9Q6Z  
for(int i=0;i<nStartPos.length;i++) KH76Vts  
{ e!O:z   
// output.writeLong(nPos); Je;HAhL  
output.writeLong(fileSplitterFetch.nStartPos); *6 P)HU@  
output.writeLong(fileSplitterFetch.nEndPos); H=7Nh6v  
} }h_= n>  
output.close(); nM&UdKf3  
} bmGtYv  
catch(IOException e){e.printStackTrace ();} I r;Z+}4>Y  
catch(Exception e){e.printStackTrace ();} O2>W#7  
} 5NAB^&{Z<X  
3D"?|rd~  
e't1.%w  
//读取保存的下载信息(文件指针位置) g7U>G=,;?U  
private void read_nPos() F6 c1YI[  
{ ]k.'~ Syz  
try{ SB2Ij',  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t:.ZvA3  
int nCount = input.readInt(); H;rLU9b  
nStartPos = new long[nCount]; Hs6}~d  
nEndPos = new long[nCount]; .LHzaeJCX  
for(int i=0;i<nStartPos.length;i++) 9$:+5f,%a  
{ Stxrgmu  
nStartPos = input.readLong(); n aB`@  
nEndPos = input.readLong(); @jevY81)  
} ,}_uk]AQ  
input.close(); 1brKs-z  
} fE/|U|5L[  
catch(IOException e){e.printStackTrace ();} ck4g=QpD{  
catch(Exception e){e.printStackTrace ();} 1$G'Kg/  
} &24z`ZS[w6  
^L;k  
/Jci1o  
private void processErrorCode(int nErrorCode) !2Q>   
{ f.SmCgG  
System.err.println("Error Code : " + nErrorCode); @:"GgkyDl#  
} GcYT<pwN6  
gC qQ~lWZ  
y()Si\9v  
//停止文件下载 6 C|]Fm  
public void siteStop() '}q1 F<&  
{ -P3;7_}]:h  
bStop = true; ,"W.A  
for(int i=0;i<nStartPos.length;i++) !,3U_!  
fileSplitterFetch.splitterStop(); _C97G&  
19t'  
T{%'"mm;  
} ?nAKB5=  
} )c$)am\I{  
//负责部分文件的抓取 eZWR)+aq  
**FileSplitterFetch.java z.7'yJIP#  
*/ rX<gcntv  
package NetFox; #)xg$9LQb  
].eY]o}=  
YQ+Kl[ec  
import java.io.*; 8?7gyp!k_f  
import java.net.*; $ (gR^L  
}w)`)N  
hsUP5_  
public class FileSplitterFetch extends Thread { k5@_8Rc  
wCb%{iowH  
P00pSRQHD  
String sURL; //File URL F^]?'`7md  
long nStartPos; //File Snippet Start Position 6/#5TdJA  
long nEndPos; //File Snippet End Position &Tf R].  
int nThreadID; //Thread's ID y=jTS  
boolean bDownOver = false; //Downing is over plY`lqm  
boolean bStop = false; //Stop identical (Rc 0l;  
FileAccessI fileAccessI = null; //File Access interface D=fB&7%@  
q$Ol"K@  
,Wp0,>!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2ju1<t,8)  
{ 2rw<]Ce  
this.sURL = sURL; e<p_u)m  
this.nStartPos = nStart; Hf/2KYZ  
this.nEndPos = nEnd; rGZ@pO2  
nThreadID = id; Ccocv>=Q&J  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [^gSWU  
} $Q:5KNF+p  
] 05Q4  
(!';  
public void run() >oc7=F<8lS  
{ uREc9z `Q'  
while(nStartPos < nEndPos && !bStop) B(MO!GNg=  
{  \~  
q<JI!n1O  
U hCd,  
try{ ,ASY &J5)7  
URL url = new URL(sURL); Yb =8\<;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #U/B,`= >  
httpConnection.setRequestProperty("User-Agent","NetFox"); hJ:Hv.{`)W  
String sProperty = "bytes="+nStartPos+"-"; 1'_OM h*;  
httpConnection.setRequestProperty("RANGE",sProperty); of& vQ  
Utility.log(sProperty); '~ ]b;nA  
<R{\pz2w  
g6W.Gl"5\w  
InputStream input = httpConnection.getInputStream(); C-6+ZIk4  
//logResponseHead(httpConnection); m Xw1%w[*  
iCx'`^HnP  
{8jG6  
byte[] b = new byte[1024]; 71/6=aq>n  
int nRead; ?qK:P  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &2\.6rb.  
{ V,M8RYOnC!  
nStartPos += fileAccessI.write(b,0,nRead); j#p3c  
//if(nThreadID == 1) I3s}t$`y(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @pko zE-  
} FyS K&  
xEiW]Eo  
5d4-95['_  
Utility.log("Thread " + nThreadID + " is over!"); n6uobo-  
bDownOver = true; Yp ? 2<  
//nPos = fileAccessI.write (b,0,nRead); &FanD   
} .HtDcGp  
catch(Exception e){e.printStackTrace ();} z(%Zji@!N  
} *@Qt*f  
} "1#,d#Q$  
3> fuH'=  
5g&'n  
//打印回应的头信息 er<~dqZ}]  
public void logResponseHead(HttpURLConnection con) Kc{wv/6}T  
{ XnG!T$  
for(int i=1;;i++) ?NwFpSB2  
{ HxM-VK '  
String header=con.getHeaderFieldKey(i); !9N%=6\  
if(header!=null) igQyn|  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1IsR}uLh  
Utility.log(header+" : "+con.getHeaderField(header)); jf2E{48P  
else !kz\ {  
break; F% |(pHk  
} JL$RBr  
} a[JgR/E@x  
;}PL/L$L6;  
'\;tmD"N5#  
public void splitterStop() 4@Qq5kpk*  
{ f Gfv{4R  
bStop = true; %$}iM<  
} /za,&7sf  
`<Ftn  
:H87x?e[  
} 9PBmBP ~  
Q7s1M&K  
lV 1|\~?4  
/* R3<+z  
**FileAccess.java aG ,uF  
*//文件访问(定位,写) G@;aqe[dB  
package NetFox; Xgm7>=l  
import java.io.*; AX)zSrXn  
O| 2Q- @D  
N$+"zJmw&  
public class FileAccessI implements Serializable{ p)ONw"sb  
Q9'p2@Z  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L9.#/%I\  
RandomAccessFile oSavedFile; g,;MV7yE  
long nPos; Uwp +w  
wfdFGoy(  
x<l1s  
public FileAccessI() throws IOException y{N9.H2  
{ U!5@$Fu  
this("",0); (X9V-4  
} x\%eg w  
MXy{]o_H~  
%L/=heBBd  
public FileAccessI(String sName,long nPos) throws IOException bm4W,  
{ dd$N4&  
oSavedFile = new RandomAccessFile(sName,"rw"); 2 zy^(%a  
this.nPos = nPos; %Z7!9+<  
oSavedFile.seek(nPos); =T-w.}27O  
} _x!pM j(A  
]ok>PH]  
I?>#neHc6  
public synchronized int write(byte[] b,int nStart,int nLen) Y8PT`7gd`  
{  q0~_D8e,  
int n = -1; +[ItkfSod!  
try{ AVp [gr  
oSavedFile.write(b,nStart,nLen); a5-\=0L~  
n = nLen; asg>TO W  
} h,x]  
catch(IOException e) IfcFlXmt2  
{ :~(im_r  
e.printStackTrace (); V%ch'  
} W%1S:2+Kl  
'T[zh#v>S  
jO 55<s94  
return n; lIz_0rE  
} z(3"\ ^T  
O[ !o1.  
PlZ iTP  
} ]D%k)<YK  
Wv"tAseu  
GcR`{ 3hO  
/* ??Zmj:8E'  
**SiteInfoBean.java sh ;uKzQ  
*/ E0Q"qEvU  
package NetFox; 7g)3\C   
F-^HN%  
k`TJ<Dv;  
public class SiteInfoBean { 91H0mP>ki  
>Mw &Tw}o  
|l xy< C4V  
private String sSiteURL; //Site's URL ?Z>.G{Wm@  
private String sFilePath; //Saved File's Path d|]O<]CG_  
private String sFileName; //Saved File's Name J\3} il N  
private int nSplitter; //Count of Splited Downloading File f_ztnRw  
gE&W6z0fJ  
v9U(sEDq  
public SiteInfoBean() |QLX..  
{//nSplitter的缺省值为5 wy {>gvqK  
//default value of nSplitter is 5 N?;o_^C  
this("","","",5); NRisr  
} rxj@NwAno  
 J4"swPf  
^Pd3 7&B4V  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YM`pNtQ  
{ ]<gCq/V#  
sSiteURL= sURL; VONAw3k7!  
sFilePath = sPath; liqR#<  
sFileName = sName; ?[VpN2*  
this.nSplitter = nSpiltter; $[iT~B$  
dAr)%RZ  
yv)nW::D(  
} rEyz|k:  
7B]:3M6d  
H [Lt%:r  
public String getSSiteURL() iv:/g|MBI&  
{ HNy/ -  
return sSiteURL; zk 5=Opmvh  
} wD ],{y  
pEVgJ/>  
:X1cA3c!  
public void setSSiteURL(String value) J+b!6t}mZn  
{ 6I>5~?#  
sSiteURL = value; 8b:clvh  
} N3gNOq&  
qX{X4b$  
p x|>v8  
public String getSFilePath() ZP6x  
{ 5U{4TeUH  
return sFilePath; }B"|z'u  
} dGsS<@G  
r|^lt7\  
8jggc#.  
public void setSFilePath(String value) .vN%UNu  
{ Er"R;l]xJ  
sFilePath = value; 1GG>.RCP  
} C[xJU6z  
g={]Mzh  
O xT}I  
public String getSFileName() goDV2 alC^  
{ aGB0-;.t7  
return sFileName; & =73D1A  
} x*me'?q  
\[hn]@@  
v Zb|!#I  
public void setSFileName(String value) 5=Kq@[(4  
{ 894r;UA7  
sFileName = value; X!o[RJY  
} 6| *(dE2x(  
7~wFU*P1  
=Kc|C~g  
public int getNSplitter() |*^8~u3J"  
{ *wC\w  
return nSplitter; [)#u<lZ<~  
} K,f* SXM  
0A#*4ap  
(9mbF%b  
public void setNSplitter(int nCount) fav5e'[$  
{ v:r D3=M-  
nSplitter = nCount; >u=%Lz"J  
} u64 @"P  
} U^%9 )4bj  
AL>c:K)qO  
X=v~^8M7%  
/* 2E^"r jLm  
**Utility.java izMYVI?0  
*/  T/[f5?p  
package NetFox; \un sh^M  
.#*D!;f  
b,#`n  
public class Utility { <57g{e0I  
Iq{o-nq  
>n]oB~P%  
public Utility() h`=r )D  
{ hZcmP"wgC1  
N99[.mErU  
gs?8Wzh90*  
} 5XDgs|8  
^^%JoQ.  
//线程睡眠 WFouoXlG0  
public static void sleep(int nSecond) i8K_vo2Z)  
{ FJ{=2]x|  
try{ G'u|Q mb1  
Thread.sleep(nSecond); dUIqDl  
} 9I85EcT^4"  
catch(Exception e) \.o=icOx  
{ iHPUmTus--  
e.printStackTrace (); W!t{rI72  
} Uo~T'mA"  
} kd yAl,  
:vpl+)n  
//日志 h\(B#SN  
public static void log(String sMsg) ML=eL*}l  
{ I!P4(3skAB  
System.err.println(sMsg); "?35C !  
} }`9jH:q-Z  
9TC) w|  
F>*{e  
public static void log(int sMsg) 5$kdgFq(  
{ S<"oUdkz  
System.err.println(sMsg); oe9lF*$/  
} Vz{>cSz#  
} z`4c 4h]I  
eIH$"f;L  
dN< , %}R  
/* |#k@U6`SG  
**TestMethod.java /2xSNalC  
*/ ?E6^!4=,  
package NetFox; c;9.KCpwx  
KFU%DU G  
Tg0CE60"  
public class TestMethod { @ &pqt6/t  
A|L'ih/  
]W/>Ldv  
public TestMethod() !J3UqS  
{ ///xx/weblogic60b2_win.exe O(c@PJem  
try{ <.bRf  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r{_>ldjq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ! \sMR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); I-kWS 4  
fileFetch.start(); BEUK}T K4  
} -R b{^/  
catch(Exception e){e.printStackTrace ();} "j^MB)YD  
bWmw3w  
2:SO_O4C  
} >P=Q #;v  
d|lpec  
Rko M~`CT  
public static void main(String[] args) cj$d=k~  
{ IeP WOpj3  
new TestMethod(); dg_Gs>?2  
} %S \8.  
} <%P2qgz5  
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