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)); Z]OXitt7
} 1j"_@?H[
for(int i=0;i<nEndPos.length-1;i++) I6@98w}"
{ Xfo3fW)s
nEndPos = nStartPos[i+1]; lV924mh
} u_ou,RF
nEndPos[nEndPos.length-1] = nFileLength; }ya@*jH
} #e)A
} P&I%!'<
"x~VXU%xU
])Rs.Y{Q5
//启动子线程 #y;TSHx/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YD>5zV%!D
for(int i=0;i<nStartPos.length;i++) jT/}5\
{ :buH\LB*P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $$'a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cC@.&
nStartPos,nEndPos,i); {P/ sxh:e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _7e ^ t N
fileSplitterFetch.start(); &ed&2t`Y
} kHMD5Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CVxqNR*DN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uT1xvXfqP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,zXP,(x
nEndPos = " + nFileLength); 3X|7 R
// fileSplitterFetch[nPos.length-1].start(); (S<Z@y+d
F/8="dM
itotn!Wb`
//等待子线程结束 {9mXJu$cc
//int count = 0; "&9L
//是否结束while循环 ={'*C7K)oK
boolean breakWhile = false; (_2Iu%F
R k'5L
Q5K<ECoPk
while(!bStop) ui>0?O*G
{ Xgb ~ED]
write_nPos(); C6<*'5T
Utility.sleep(500); XHN*'@ 77;
breakWhile = true; b\ P6,s'(
mHj3ItXUu
{:@MBA34
for(int i=0;i<nStartPos.length;i++) S{uKm1a
{ nO;*Peob
if(!fileSplitterFetch.bDownOver) 85{2TXQ^%=
{ lhk=yVG3
breakWhile = false; KzgW+6*G
break; :NCY6? [Dz
} Ng Jp2ut
} J`I^F:y*
if(breakWhile) l^~E+F~
break; 4hQ.RO
r}>q*yx:
'!V5 #J
//count++; Q|$?d4La8
//if(count>4) 1J{1>r
// siteStop(); 31cC*
} NP+*L|-;
NT1"?Thx|
XT"-
System.err.println("文件下载结束！"); bjq+x:>
} =cP7"\
catch(Exception e){e.printStackTrace ();} HxE`"/~.7k
} arQEi
TXH9BlDn
5YG%\
//获得文件长度 G+k~k/D6
public long getFileSize() s7 K](T4
{ s{Wj&.)M
int nFileLength = -1; RJ63"F $
try{ 9im<J'
URL url = new URL(siteInfoBean.getSSiteURL()); H)@f_pfj(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n[f<]4<
httpConnection.setRequestProperty("User-Agent","NetFox"); 12olVTuw
kv8 /UW
Nn:>c<[
int responseCode=httpConnection.getResponseCode(); 2D vKW%;
if(responseCode>=400) *z3wm-z1&
{ VNggDKS~K
processErrorCode(responseCode); .I1k+
return -2; //-2 represent access is error 7[/1uI9U8K
} ]A.tauSW
:}n\ r/i
YT@D*\
String sHeader; cy%S5Rz
lDU@Q(V#}<
U%qE=u-
for(int i=1;;i++) `9>1 w d
{ ^DaP^<V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 24; BY'
//Utility.log(in.readLine()); @TqqF:c7
sHeader=httpConnection.getHeaderFieldKey(i); {wS)M
if(sHeader!=null) MEled:i
{ w1q`
if(sHeader.equals("Content-Length")) xA7Aw0
{ #y2IHO-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s<hl>vY_'
break; ^:Hx.
} *$6dNx
} &40# _>W7
else rd\:.
break; aZBS!X
} XqxmvN
} NW AT"
catch(IOException e){e.printStackTrace ();} 5p]Cwj<u
catch(Exception e){e.printStackTrace ();} M7x*LiKc2
lq[o2\
+jifbf-
Utility.log(nFileLength); s/cclFji]
(h$[g"8
83[gV@LW0m
return nFileLength; O% }EpIP_
} 3Gyw^_{J
#eZm)KFQg
,fR/C
//保存下载信息（文件指针位置） O_bgrXg6x
private void write_nPos() AJWV#J%nB
{ ]@G$L,3
try{ <Z:Fnp
output = new DataOutputStream(new FileOutputStream(tmpFile)); )i$:iI >k
output.writeInt(nStartPos.length); mQiVTIP3[O
for(int i=0;i<nStartPos.length;i++) =e j'5m($3
{ S`?L\R.:
// output.writeLong(nPos); F&[MyXU4
output.writeLong(fileSplitterFetch.nStartPos); A."]6R<
output.writeLong(fileSplitterFetch.nEndPos); I4RUXi 5
} K H&o`U(}
output.close(); -Rcl(Q}LZ
} +`_Km5=
catch(IOException e){e.printStackTrace ();} A KjCm*K(q
catch(Exception e){e.printStackTrace ();} T:?01?m
} 8-clL\bm
|(Q !$
+ia N[F$
//读取保存的下载信息（文件指针位置） TLWU7aj&!
private void read_nPos() 1nAAs;`'
{ ;:l>Kac
try{ FKpyD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2nsW)bd
int nCount = input.readInt(); ~d\>f
nStartPos = new long[nCount]; 4Y!_tZ>
nEndPos = new long[nCount]; ?x-:JME0
for(int i=0;i<nStartPos.length;i++) "(cMCBVYdA
{ YgfQ{3^I
nStartPos = input.readLong(); )(`HEl>-9c
nEndPos = input.readLong(); KsR^:_e
} ?loP18S b
input.close(); g]a5%8*{
} W{js9$oJ
catch(IOException e){e.printStackTrace ();} 9 U!-Zn!
catch(Exception e){e.printStackTrace ();} ?jy6%Y#,i
} x}(p\Efx
%hO/2u
1,pg7L8H
private void processErrorCode(int nErrorCode) WAWy3i
{ WiBO8N,%`
System.err.println("Error Code : " + nErrorCode); 9EIOa/*
} >ngP\&\
R[Y{pT,AY
5L%\rH&N
//停止文件下载 ujH ^ML
public void siteStop() q\q8xF~[p
{ S{.G=O
bStop = true; )xPfz
for(int i=0;i<nStartPos.length;i++) #G`UR
fileSplitterFetch.splitterStop(); gxf{/EjH
c(5r
[\ALT8vC?m
} !GL kAV
} 8IrA{UU
//负责部分文件的抓取 s+RSAyU
**FileSplitterFetch.java Wd78 bu|
*/ KMo]J1o
package NetFox; .*_uXQ
[<H'JsJl
2zQ62t}
import java.io.*; y^xEZD1X6-
import java.net.*; {=)g?!zC
;{%R[M'
CQGq}.Jt!
public class FileSplitterFetch extends Thread { Jg:%|g
@}[yC['
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String sURL; //File URL AIK99
long nStartPos; //File Snippet Start Position ay-M.J
long nEndPos; //File Snippet End Position h:qt?$]J
int nThreadID; //Thread's ID )CAEqP
boolean bDownOver = false; //Downing is over dd&n>A3O=
boolean bStop = false; //Stop identical G+dQ" cI9
FileAccessI fileAccessI = null; //File Access interface 34e>R?J
L2GUrf
LLlt9(^d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -o`Eka!ELz
{ FWu[{X;
this.sURL = sURL; :#I7);ol
this.nStartPos = nStart; k.MAX8
this.nEndPos = nEnd; ,KO_h{mI<
nThreadID = id; 9+!1jTGSkf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F4T}HY>nZ
} gqCDF H
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RqnT*
public void run() WhY8#B'?
{ ^P| K2at
while(nStartPos < nEndPos && !bStop) )08mG_&atL
{ D;RZE
bm Hl\?
oI/jGyY;
try{ F9Y/Z5 Ea
URL url = new URL(sURL); xdqiogue
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'c")]{
httpConnection.setRequestProperty("User-Agent","NetFox"); %?`TyVt&0
String sProperty = "bytes="+nStartPos+"-"; vI)-Zz[3
httpConnection.setRequestProperty("RANGE",sProperty); Vu u2SS
Utility.log(sProperty); &-s/F`
4PVkKP'/
l[)ZEEP
InputStream input = httpConnection.getInputStream(); l'#P:eW
//logResponseHead(httpConnection); -55Pvg0ND
'&<T;V%
/6$8djw
byte[] b = new byte[1024]; 9*"Ae0ok1
int nRead; j!oD9&W4~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^71!.b%
{ BRu/pyxG
nStartPos += fileAccessI.write(b,0,nRead); 5V{ B,T
//if(nThreadID == 1) Z6Owxqfht
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >>'t7U##
} Gl+Ql?|
.%iJin"
YjV-70'
Utility.log("Thread " + nThreadID + " is over!"); rTR4j>Ua~
bDownOver = true; =h#3D?b0n
//nPos = fileAccessI.write (b,0,nRead); AhjUFz
} ylEQeN
catch(Exception e){e.printStackTrace ();} ;T6x$e
} C9`J6Uu
} oZY2K3J)
7xmyjy%c
1 >nl ]yO
//打印回应的头信息 axRzn:f
public void logResponseHead(HttpURLConnection con) L;n2,b
{ ?&H1C4
for(int i=1;;i++) <NLor55.]
{ 7d7"^M
String header=con.getHeaderFieldKey(i); A=v^`a03I
if(header!=null) 5K~kzRL$r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jmcb-=ts
Utility.log(header+" : "+con.getHeaderField(header)); ~"Pu6-\VT
else QTN _Z#'
break; ?Q~6\xA
} /<HEcB
} I1H} 5bf3
A1zqm_X5)P
1-Fz#v7p
public void splitterStop() "iCR68e
{ &*I\~;1
bStop = true; 09f:%!^u
} <eObQ[mQ
yMQuM:d
:y?xS
} P(_wT:8C?
8-N8v *0
blwdcdh
/* $II[b-X?S
**FileAccess.java =sqhPS<>
*//文件访问(定位，写) H$^b.5K
package NetFox; )C @W_cfMN
import java.io.*; |P_\l,f8`
<&7KcvBn"4
+F &,,s"&
public class FileAccessI implements Serializable{ q;T3bxp+
&&0,;r,-)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U&fOsx?"
RandomAccessFile oSavedFile; Lp; {&=PIo
long nPos; sOSol7n
f`5e0;zm
kIAWI;H{
public FileAccessI() throws IOException }+[H~8)5
{ {emO&#=@CP
this("",0); m6aq_u{W
} uiO7sf6
U!:Q|':=h
EDR;" G(N
public FileAccessI(String sName,long nPos) throws IOException ."R,j|o6
{ G<kslTPyq
oSavedFile = new RandomAccessFile(sName,"rw"); /r#.BXP
this.nPos = nPos; i|X ;n
oSavedFile.seek(nPos); `~Eo;'(+^
} IqK??KSC
Y{X79Rd
J4qFU^
public synchronized int write(byte[] b,int nStart,int nLen) tT}*%A
{ T}(J`{9i
int n = -1; ]X,C9
try{ 4h>Dpml
oSavedFile.write(b,nStart,nLen); @O}%sjC1
n = nLen; >]q{vKCAP
} fX).A`
catch(IOException e) 4P@Ak7iL(V
{ G#ov2
e.printStackTrace (); } h|1H
} :E/]Bjq$;
/dpEL9K
+K4d(!Sb
return n; 'c 0]8Y4
} kP9DCDO`[5
z'K&LH
`}gjfu -'\
} 'qS&7 W(
B&&:A4
'~RP+
/* YaJ[39V
**SiteInfoBean.java q3\ YL?
*/ * 8n0
package NetFox; xJ>U_Gd
{-IH?!&v
bCY8CIF
public class SiteInfoBean { ^>02,X mk
K'.aQ&2
GU'/-6-T
private String sSiteURL; //Site's URL JQQP!]%}
private String sFilePath; //Saved File's Path 0R&$P6
private String sFileName; //Saved File's Name o5dPE{f
private int nSplitter; //Count of Splited Downloading File d^sS{m\
ZI4[v>
)IQa]A
public SiteInfoBean() Md_S};!QN6
{//nSplitter的缺省值为5 bhaIi>W~G
//default value of nSplitter is 5 e[f}Lxln
this("","","",5); 4$LVl
} @l:\0cO
BwwOaO@L
6qQdTp{i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [F4]pR(
{ cl kL)7RQ
sSiteURL= sURL; 7 sv 3=/`
sFilePath = sPath; sJ[I<
sFileName = sName; +jQHf-l
this.nSplitter = nSpiltter; }t}y
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$'FPsoH
} `R@1Sc<*|
F}p)Q$0
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public String getSSiteURL() P%MYr"<$E
{ H&`0I$8m
return sSiteURL; W8{g<. /
} 7M;7jI/C
KITC,@xE_O
Q!7il<S
public void setSSiteURL(String value) / i[F
{ jd]Om r!
sSiteURL = value; 7]se!k,
} s`Z| A
m,YBk<Bx
0;9X`z J
public String getSFilePath() @I_!q*
{ jpijnz{M
return sFilePath; LsB|}_j7
} ]\DZW4?'
e$'|EE.=q+
!R@v\Eu
public void setSFilePath(String value) 4yy9m8/
{ 6! `^}4
sFilePath = value; EjxzX1:
} .d mUh-
aY:u-1
@`"UD
public String getSFileName() haNi[|
{ O^/z7,
return sFileName; h"O4r8G}
} G,o5JL"t
nh"8on]M~
4WspPHj
public void setSFileName(String value) z{;~$."
{ Z'hHXSXM
sFileName = value; l-/fFy)T
} lqaOLZH
s>pM+PoGYd
&Ul8h,qw
public int getNSplitter() /i:c!l9
{ faTp|T`nY
return nSplitter; Lp1\vfU<+
} dMw7UJ
*I)F5M
`2 6t+Tb
public void setNSplitter(int nCount) 4eD>DW
{ 85e!)I_
nSplitter = nCount; UO~Xzx!e
} {wK|C<K
} ,M?K3lG\g[
|[+/ ]Y
X}fu $2
/* J?y0RX
**Utility.java "A9qC*6[
*/ *@+E82D
package NetFox; >U7{EfUJdx
Mp-hNO}.Z
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public class Utility { wk9qyv<
;N(9nX}%)
_48@o^{
public Utility() r)]8zK4;=
{ %mFZ!(
;0"p)O@s04
Bx" eX>A8
} l$:?82{
Rlwewxmr
//线程睡眠 gcI?)F
public static void sleep(int nSecond) n=iL6Yu(
{ v\ <4y P
try{ \c(Z?`p]R1
Thread.sleep(nSecond); p|0ZP6!|
} wSPwa,)7s
catch(Exception e) !kQJ6U
{ . UaLP
e.printStackTrace (); a<CJ#B2K
} T*1`MIkv
} L"[>tY
,t|qhJF
//日志 jccSjGX@w
public static void log(String sMsg) {8e4TD9E0
{ P.Gmj;
System.err.println(sMsg); q/eod
} phP%
c`s ]ciC
w|[{xn^R
public static void log(int sMsg) N_o|2
{ =u<jxV9
System.err.println(sMsg); Vg^,Ky,
} ZxoAf;U~
} c4 bo
3R?6{.
*wl&Zzx
/* kJNu2S
**TestMethod.java j<PpCL_8%
*/ YF$nL(
package NetFox; DTN)#GCtF
s<'WTgy1i
E5Zxp3N
public class TestMethod { <d~IdK'\x
VpyqVbx1
/;;$9O9
public TestMethod() LA4,o@V`
{ ///xx/weblogic60b2_win.exe PM8*/4Cu.5
try{ `%$l b:e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3FsX3K,_X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lnWscb3t
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gq =i-I
fileFetch.start(); =v6qr~
} 60X))MyN
catch(Exception e){e.printStackTrace ();} ]EfM;'j[
W0\ n?$ZC~
}~!KjFbs
} RCY}JH>}
b0aV?A}th
@WnW @'*F
public static void main(String[] args) Tu7}*vsR
{ H|s,;1#
new TestMethod(); fYiof]v@_m
} 7CSd}@71\
} KOit7+Q
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