http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #qk A*WP
} #`C;@#xr
for(int i=0;i<nEndPos.length-1;i++) @t
{ PEPBnBA&1
nEndPos = nStartPos[i+1]; mlR*S<Z
} !TRJsL8
nEndPos[nEndPos.length-1] = nFileLength; tVZjtGz=
} xFpMn}CD
} $e;_N4d^
`um#}ify#
LX e{
//启动子线程 )jK"\'cK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 38dXfl
for(int i=0;i<nStartPos.length;i++) fmvX;0O
{ Z4Nl{ 6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bGvALz'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V@Z8t8
nStartPos,nEndPos,i); Z~tOR{q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zQ$*!1FmN
fileSplitterFetch.start(); [e )j,Q1
} xD;5z`A3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A+T!DnVof
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zLlu%Oc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M?4)U"_VE
nEndPos = " + nFileLength); Vc3tKuMsiX
// fileSplitterFetch[nPos.length-1].start(); 3y%B&W,sm
c,1Yxg]|
kmM1)- v
//等待子线程结束 ]k%Yz@*S
//int count = 0; 'w`:p{E
//是否结束while循环 (z0S5#g ,x
boolean breakWhile = false; o[Yxh%T
Da!A1|"
~jb6
while(!bStop) #]i*u1
{ /a%5!)NE%
write_nPos(); &,xN$
Utility.sleep(500); #N%xr'H
breakWhile = true; UfEF>@0
5tg
1O1/P,u+
for(int i=0;i<nStartPos.length;i++) 4!<8Dd
{ "z\T$/
if(!fileSplitterFetch.bDownOver) }+0{opY4R
{ BF2,E<^A
breakWhile = false; Dx =ms^oN5
break; /i$ mIj`
} ^zHBDRsb2F
} 15_OtK
if(breakWhile) BhkJ>4#
break; nZa.3/7dJ
TdI5{?sW
mxhO:.l
//count++; (b Q1,y
//if(count>4) @kUCc1LT
// siteStop(); g]R }w@nJ
} M-u:8dPu
<k'=_mC_
+qe!KPk2
System.err.println("文件下载结束！"); ow*) 1eo
} ci>+Zi6
catch(Exception e){e.printStackTrace ();} 7</&=lly
} D[m;rcl
OS6 l*S('
@CU3V+
//获得文件长度 ]:JoGGE a0
public long getFileSize() a|`Pg1j#
{ :3$WY<
int nFileLength = -1; .oYUA}
try{ Fd-PjW/E8
URL url = new URL(siteInfoBean.getSSiteURL()); v2:A 4Pd:+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y@N}XH<4R
httpConnection.setRequestProperty("User-Agent","NetFox"); (7q!Z!2
(,`ypD+3q
4mJ4)
int responseCode=httpConnection.getResponseCode(); ~`c?&YixU
if(responseCode>=400) -Zd!0HNW1
{ <<gk<_7`
processErrorCode(responseCode); YYHtd,0\+
return -2; //-2 represent access is error 2e zQX2q
} CN@bJo2
M ()&GlNs
2J =K\ L
String sHeader; LFob1HH*8
Z:W6@j-~
*{8Kb>D
for(int i=1;;i++) Eym<DPu$n
{ L8N`<a5T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6+(g4MW
//Utility.log(in.readLine()); ,qV8(`y_
sHeader=httpConnection.getHeaderFieldKey(i); +M!f}=H
if(sHeader!=null) pi:%Bd&F
{ r k;k:<c
if(sHeader.equals("Content-Length")) ^AK<]r<?L?
{ WY#A9i5Ge
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XeDiiI
break; `;4P?!WG
} Ro$'|}(+A
} K O"U5v
else =4uL1[0'
break; Mib(J+Il
} %mPIr4$Pg
} e5_a.c
catch(IOException e){e.printStackTrace ();} U7O~ch[,
catch(Exception e){e.printStackTrace ();} ?9nuL}m!a
$5ZBNGr
{^2``NYM_
Utility.log(nFileLength); eWSA
PXG)?`^NX
S\K;h/;V
return nFileLength; }z1aKa9
} .5'M^
3JM0 m (
MW8GM}Ho[
//保存下载信息（文件指针位置） 6=s!~
private void write_nPos() #z_lBg. K
{ >&3M #s(w
try{ JsI`#
output = new DataOutputStream(new FileOutputStream(tmpFile)); m07= _4
output.writeInt(nStartPos.length); |u8IQR'B
for(int i=0;i<nStartPos.length;i++) X&fM36o7
{ Hj't.lg+j
// output.writeLong(nPos); wl H6
output.writeLong(fileSplitterFetch.nStartPos); z[X>>P3<n
output.writeLong(fileSplitterFetch.nEndPos); Fg<$;p
} p'fq&a+
output.close(); M_*"g>Z
} <7R\#
catch(IOException e){e.printStackTrace ();} A ><
catch(Exception e){e.printStackTrace ();} u8L%R[#o
} YKKZRlQo
hRTw8-wy:
NpqMdd
//读取保存的下载信息（文件指针位置） B-PN +P2
private void read_nPos() ;X,|I)
{ {J;[ Hf5
try{ WzZ<ZCHm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @S\!wjl]C
int nCount = input.readInt(); Ya{$:90(4
nStartPos = new long[nCount]; H)z}6[`
nEndPos = new long[nCount]; 4Ra
for(int i=0;i<nStartPos.length;i++) 2%UzCK
{ TeaP\a
nStartPos = input.readLong(); Q.X)QCp#r
nEndPos = input.readLong(); UIgs/
} "1|n]0BF
input.close(); 2\80S[f
} ?aOx b
catch(IOException e){e.printStackTrace ();} >Lj0B%^EvM
catch(Exception e){e.printStackTrace ();} =i[_C>U
} =]jc{Y%o
2#LTd{
jsB%RvX
private void processErrorCode(int nErrorCode) =n.d'
{ w%F~4|F
System.err.println("Error Code : " + nErrorCode); /ap3>xkt
} ){^o"A?-:
KGb:NQ=O6i
.Qk T-12
//停止文件下载 ))m\d*
public void siteStop() ln.'}P
{ {7swE(N
bStop = true; EYWRTh
for(int i=0;i<nStartPos.length;i++) y,'M3GGl
fileSplitterFetch.splitterStop(); `L# pN5
1) 7n (
#4UKkd
} mU@pRjq=
} k|V%*BvY>
//负责部分文件的抓取 Nki08qZ[
**FileSplitterFetch.java D! TFb E
*/ ramYSX@
package NetFox; ]S!:p>R
M ,!Dhuas
RlW0U-%u
import java.io.*; ]e`&py E
import java.net.*; C#<b7iMg
&h^E_]P
}#%3y&7M7
public class FileSplitterFetch extends Thread { ZNWo:N8;
*} @Y"y
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String sURL; //File URL I)7STzlMj.
long nStartPos; //File Snippet Start Position b>g&Pf#N!
long nEndPos; //File Snippet End Position xE>H:YPm
int nThreadID; //Thread's ID 6L5j
boolean bDownOver = false; //Downing is over Q8-;w{%
boolean bStop = false; //Stop identical N,kPR
FileAccessI fileAccessI = null; //File Access interface i/UDda"E
J:W|2U="
)B"k;dLm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W^dk:
{ lGoP(ki
this.sURL = sURL; TOF_m$@#
this.nStartPos = nStart; >?3yVE
this.nEndPos = nEnd; s'$5]9$S
nThreadID = id; _[%2QwAUj*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J>D+/[mFt
} aE aU_f/
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zD}@QoB
public void run() X=C*PWa7
{ ?XCFRt,ol
while(nStartPos < nEndPos && !bStop) T0HNld
{ @nWhUH%
DA=#T2)p
|!t&ZpdD
try{ 9t$#!2z
URL url = new URL(sURL); *Wbs{>&No
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hSAdD!
httpConnection.setRequestProperty("User-Agent","NetFox"); oVZI([O
String sProperty = "bytes="+nStartPos+"-"; XotiKCk|Aq
httpConnection.setRequestProperty("RANGE",sProperty); rF@njw@
Utility.log(sProperty); /;5U-<qf
1`6kc9f.
@FNaCmBX
InputStream input = httpConnection.getInputStream(); stxei 6
//logResponseHead(httpConnection); >T{Gl/? p
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J[|4`GT
byte[] b = new byte[1024]; &,DZ0xA
int nRead; Fh8 8DDJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L i g7Ac,
{ c/Dk*.xy<
nStartPos += fileAccessI.write(b,0,nRead); O$eNG$7
//if(nThreadID == 1) )wZ;}O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L<D<3g|4
} 8NF93tqD6
p]jkfsCjN
SI)QX\is8
Utility.log("Thread " + nThreadID + " is over!"); }>93X0%r
bDownOver = true; 4 H<.
//nPos = fileAccessI.write (b,0,nRead); R!)3{cjU@
} nu(;yIRP
catch(Exception e){e.printStackTrace ();} Ppton+?(
} mV>l`&K=
} we("#s1=
{{:QtkN
9-/u _$
//打印回应的头信息 s78MXS?py
public void logResponseHead(HttpURLConnection con) /]1$Soo
{ ^5'pJ/BV
for(int i=1;;i++) EjA3hHJ
{ uqotVil,
String header=con.getHeaderFieldKey(i); nsA}A~(E
if(header!=null) !V^wq]D2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q6 oM$qiM
Utility.log(header+" : "+con.getHeaderField(header)); '^|u\$&U
else M&[bb $00j
break; 8NZQTRdH
} J#'8]p3E
} }AW"2<@
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mAM:Q*a'
public void splitterStop() 9}|x N8
{ jd.{J{o
bStop = true; :{LNr!I?I
} ;!hwcOkX
[%c5MQ?H
\<aR^Sj.
} A.9ZFFz
+$YHdgZ.
$2E&~W %
/* nl-y0xD9c
**FileAccess.java |1pDn7
*//文件访问(定位，写) 5O%?J-Hp
package NetFox; 29HyeLB@
import java.io.*; ^O3i)GO
_. &N@k
gF>t+"+x
public class FileAccessI implements Serializable{ Pihpo
7_Op(C4,nC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~H c5M5m
RandomAccessFile oSavedFile; *e25!#o1
long nPos; b%QcB[k[WB
ES)@iM?5
?j;,:n
public FileAccessI() throws IOException r3NdE~OAi
{ h e[2,
this("",0); nN2huNTf:
} ES\=MO5a7
K|Xr~\=
&Nw[J5-"k
public FileAccessI(String sName,long nPos) throws IOException r4M;]
{ c2u*<x
oSavedFile = new RandomAccessFile(sName,"rw"); kIR/.Ij}
this.nPos = nPos; \<HY'[gr
oSavedFile.seek(nPos); 8shx7"
} |s,y/svp
f~R+Q/Gtz`
d2?#&d'aq
public synchronized int write(byte[] b,int nStart,int nLen) s6QD^[
{ 7]_zWx,r
int n = -1; CiV^bYi
try{ r=/$}l4
oSavedFile.write(b,nStart,nLen); <1#hX(Q
n = nLen; S%jW}v';
} N9s+Tm
catch(IOException e) #5=W[+4eN
{ 26;Gt8
e.printStackTrace (); Sf*gAwnW
} &xpvHKJl
q+} \(|
#-o 'g!
return n; k=cDPu -
} z+{xW7
IL1iTRH
.Q^V,[on1T
} phQ{<wzwp
(I#mo2
' &3,qT
/* hV+=hX<h
**SiteInfoBean.java ^]D+H9Tl
*/ E3] 8(P%D-
package NetFox; * F_KOf9p
vOLa.%X]h
rHi4Pw{L
public class SiteInfoBean { |+KwyHE`9
i5=~tS
{5fL!`6w
private String sSiteURL; //Site's URL 2C1NDrS;}
private String sFilePath; //Saved File's Path LJom+PxF$x
private String sFileName; //Saved File's Name Wffz&pR8
private int nSplitter; //Count of Splited Downloading File 7<Qmpcp =
WEJ-K<A(
. :>e"D
public SiteInfoBean() d"n"A?nXh
{//nSplitter的缺省值为5 xQ2:tY#?
//default value of nSplitter is 5 ,p#r; O<O
this("","","",5); I~6 o<HO
} =6+99<G|%M
X# /c7w-
mYj)![
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AWE ab
{ \*Yr&Lm
sSiteURL= sURL; rL&Mq}7QK
sFilePath = sPath; jEwt1S V
sFileName = sName; c&x1aF "B
this.nSplitter = nSpiltter; :5.F
V#5$J Xp
U82mO+}
} J3(E{w8Q
4 R(m$!E!
HTv#2WX
public String getSSiteURL() ?3 k_YN"
{ ]31=8+D
return sSiteURL; !%D';wQ,/
} !nvg:$.&
x}nBUq:
3kk^hvB+f
public void setSSiteURL(String value) 15q^&l[Q
{ )TKn5[<4
sSiteURL = value; (Li0*wRb
} zsd1n`r
Wy*+8~@A
dgIH`<U$
public String getSFilePath() 9X%: ){
{ 0?(uqjD:
return sFilePath; Goc?HR
} q5L^>"
."=%]l0
|q8N$m
public void setSFilePath(String value) la)^`STh
{ "bDj00nwh
sFilePath = value; }]PHE(}7
} \D(3~y>
1^2Q`~,g
<nN.$4~X
public String getSFileName() jU7[z$GX
{ l_yF;5|?z
return sFileName; ;>f\fhi'
} 3l45(%g+
(XW'1@b
E5@=LS
public void setSFileName(String value) xOAq!,|V
{ vq^';<Wh.
sFileName = value; *i^$xjOa
} ]K*R[
gwQMy$
5h`LWAB
public int getNSplitter() )\ceanS
{ 7=9>yba)^
return nSplitter; Su"Z3gm5Kw
} 9Dgs A`{$
"C\yM{JZ
FRZ]E)9Z]b
public void setNSplitter(int nCount) {_\cd.AuT
{ oKCy,Ot<
nSplitter = nCount; /\b* oPWJ
} *jbPy?%oY
} 9\<q=p~
N`,\1hHMT
3 dJ362
/* !cYID \}S,
**Utility.java X,_K )f
*/ 0bM_EC
package NetFox; %" 7UYLX
-` ViuDX=
=g!Pw]
public class Utility { {yWL|:#K
VOM@x%6#c
Wp8>Gfb2
public Utility() Ycspdl+(S$
{ vN\[2r%S
V%PQlc.X
`Ucj_6&Tqs
} D@gC(&U/6
+cqUp6x.
//线程睡眠 JJ ?'<)EF
public static void sleep(int nSecond) p|2GPrA]aL
{ xxvt<J
try{ 4S~kNp$
Thread.sleep(nSecond); A1-,b.Ni
} \ *[Ht!y
catch(Exception e) P.@dB.Ny
{ 7Tdx*1 U
e.printStackTrace (); }7 +%k/
} /go[}X5QR[
} qe{;EH*
8IRKCuV
//日志 n|&=6hiI
public static void log(String sMsg) X5[vQ3^
{ qi7C.w;
System.err.println(sMsg); U\H[.qY-
} ].kj-,5>f
O5-GrR^yt
} SWp~3P
public static void log(int sMsg) 5~?6]=hl
{ $j\>T@
System.err.println(sMsg); QrK%DN
} UtTlJb{-j
} CU\gx*=E
{%u^O/M
`x/i1^/_@
/* x>Q% hl
**TestMethod.java 'Xj^cX
*/ d=qVIpZ
package NetFox; V&:x+swt
/qy6YF8;y
m\XsU?SuX
public class TestMethod { !>> A@3
%K|f,w=m
M' z.d
public TestMethod() L<@*6QH
{ ///xx/weblogic60b2_win.exe 5)'Y\~2
try{ ajk}&`Wj"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B2Y.1mXq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NL$z4m0
SiteFileFetch fileFetch = new SiteFileFetch(bean); }k-8PG =
fileFetch.start(); ^rO"U[To
} E#:!&{O
catch(Exception e){e.printStackTrace ();} G`O*AQ}[
n]$rLm%^
VtI`Qcjc
} [(x*!,=
Y?J/KW3
5aW#zgxXg
public static void main(String[] args) 0j(U &
{ wB0vpt5f
new TestMethod(); yjL+1_"B
} ?SFQx\/
} j [lS.Lb
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