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)); DmiBM6t3N
} 9oWU]A\k>
for(int i=0;i<nEndPos.length-1;i++) 9)q3cjP{<
{ 7~/cz_
nEndPos = nStartPos[i+1]; SAx9cjj+
} yGZsNd {a&
nEndPos[nEndPos.length-1] = nFileLength; {m.$EoS
} u/zBz*zh
} V2YK T,5
:]^e-p!z
!~@GIr
//启动子线程 ff"wg\O4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5'~_d@M
for(int i=0;i<nStartPos.length;i++) jVj5; }
{ J!6FlcsZm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ggr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gE-y`2SU
nStartPos,nEndPos,i); `FP?9R6Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E9HMhUe
fileSplitterFetch.start(); ^mS |ff
} AZtS4]4G)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XpIiJry!6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /:&!o2&1H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zp_(vOc
nEndPos = " + nFileLength); hRcb}>pr
// fileSplitterFetch[nPos.length-1].start(); IV QH p
NR{wq|"
+]db-
//等待子线程结束 2ej7Ql_@c
//int count = 0; t8Zo9q>
//是否结束while循环 uy'ghF
boolean breakWhile = false; .J"N}
'=\}dav!
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while(!bStop) "n-'?W!
{ ( ?V`|[+u
write_nPos(); e%4?-{(
Utility.sleep(500); \INH[X#>
breakWhile = true; 1SQATUV
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S)rZE*~2
for(int i=0;i<nStartPos.length;i++) E-MPFL
{ ));#oQol9
if(!fileSplitterFetch.bDownOver) !,WGd|oJ
{ T)C@6/
breakWhile = false; e_vsiT
break; g|=_@ pL
} ?HZp@&
} cw;wv+|k
if(breakWhile) -wlj;U
break; 3:%k pnO
9N]Xa
^6 6!f 5^W
//count++; k_=SDm a
//if(count>4) D-3[#~MV
// siteStop(); x^f<G 6z
} r;cDYg
od;-D~
X@nBj;
System.err.println("文件下载结束！"); 0r]n 0?x
} ><%585
catch(Exception e){e.printStackTrace ();} +bjy#=
} $o6/dEKQ
-H1=N
2`yhxO
//获得文件长度 We+rFk1ddt
public long getFileSize() ~{c ?-qb
{ l=^A41L_
int nFileLength = -1; O--p)\
try{ BEZ~<E&0H
URL url = new URL(siteInfoBean.getSSiteURL()); A#uU]S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4"@<bKx
httpConnection.setRequestProperty("User-Agent","NetFox"); tz1@s nes
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fV:15!S[
int responseCode=httpConnection.getResponseCode(); e~h>b.~
if(responseCode>=400) ^df wWP
{ wNONh`b
processErrorCode(responseCode); GqFx^dY4*
return -2; //-2 represent access is error p_r`"
} ];r! M0
(1/Sf&2i
8K8u|]i
String sHeader; # @\3{;{R
*miG<
P\7DA4]
for(int i=1;;i++) $+gQnI3w
{ \u=d`}E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;i{B,!#
//Utility.log(in.readLine()); vz^ ] g
sHeader=httpConnection.getHeaderFieldKey(i); u ExLj6
if(sHeader!=null) $+eeE
{ <y 4(!z"
if(sHeader.equals("Content-Length")) _S!^=9bJ
{ -oD,F $Rb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U}2@
break; u#05`i:Z
} 0JR/V68$
} ; :e7Z^\/k
else |T#cq!
break; ^0,}y]5p
} PZ[-a-p40
} iUKjCq02
catch(IOException e){e.printStackTrace ();} eSPS3|YYn
catch(Exception e){e.printStackTrace ();} FT).$h~+4
uJ`N'`Z
q|5WHB
Utility.log(nFileLength); ITPE2x
:@w~*eK~
VPN 9 Ql=
return nFileLength; BD6!,
} x;ik
z:'m50'
~tUZQ5"
//保存下载信息（文件指针位置） N$=YL @m8
private void write_nPos() o:8ns m
{ r#-
try{ hvt]VC]]
output = new DataOutputStream(new FileOutputStream(tmpFile)); N2h5@*1Y
output.writeInt(nStartPos.length); 0%xktf
for(int i=0;i<nStartPos.length;i++) e9acI>^w
{ 3mgvWR
// output.writeLong(nPos); Vjs2Yenx
output.writeLong(fileSplitterFetch.nStartPos); Rtf<UhUn
output.writeLong(fileSplitterFetch.nEndPos); 5nPvEN/
} Kq7r+A
output.close(); &-/J~b)"
} %Tp9GGt
catch(IOException e){e.printStackTrace ();} H UJqB0D ?
catch(Exception e){e.printStackTrace ();} 6/!:vsa"3
} ueg%yvO
YB*)&@yx
.+7n@Sc
//读取保存的下载信息（文件指针位置） )St0}?I~
private void read_nPos() gD$&OkH
{ |dIR v
try{ G>~/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l6zAMyau5
int nCount = input.readInt(); besc7!S
nStartPos = new long[nCount]; f:j:L79}
nEndPos = new long[nCount]; ;&lXgC^*
for(int i=0;i<nStartPos.length;i++) Q-)(s
{ \^1^|a"
nStartPos = input.readLong(); 8;M,l2pmR{
nEndPos = input.readLong(); k(f),_
} 6@aH2+4+
input.close(); /{R ^J#
} G-CL \G\n
catch(IOException e){e.printStackTrace ();} =K@LEZZ'/<
catch(Exception e){e.printStackTrace ();} mmQC9nZ
} F,YPIl
m.P F'_)/
c|%5SA
private void processErrorCode(int nErrorCode) azZ|T{S
{ :F d1k Jm
System.err.println("Error Code : " + nErrorCode); Rd(8j+Q?ps
} n6[shXH
I/'>MDB!
hMupQDv/I
//停止文件下载 K-YxZAf
public void siteStop() 2?(/$F9X,
{ fe\'N4
bStop = true; -raK
for(int i=0;i<nStartPos.length;i++) xK8m\=#
fileSplitterFetch.splitterStop(); Fpo}UQQbc
t:dvgRJt*
QM!UMqdj
} B^19![v3T
} 6rS ? FG=
//负责部分文件的抓取 f$</BND
**FileSplitterFetch.java tzl,r"k3
*/ 6oKlr,.
package NetFox; `-nSH)GBM
nUY)LnI
C\rT'!Uk\Q
import java.io.*; y**L^uvr
import java.net.*; 7|Vpk&.>
]Y & 2&
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public class FileSplitterFetch extends Thread { L9[m/(:y
XW'7
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String sURL; //File URL m:EYOe,w
long nStartPos; //File Snippet Start Position r?`nc6$0|
long nEndPos; //File Snippet End Position r& RJ'z
int nThreadID; //Thread's ID aSm</@tO&
boolean bDownOver = false; //Downing is over YC{7;=Pf
boolean bStop = false; //Stop identical q9zeN:><
FileAccessI fileAccessI = null; //File Access interface u`L*
VQ~eg wJL
nP=/XiCj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E?0RR'
{ Kd#64NSi$A
this.sURL = sURL; ~9fTs4U
this.nStartPos = nStart; cP21x<n
this.nEndPos = nEnd; hHt.No
nThreadID = id; LGy!{c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]~WIGl"g
} esTK4z]
B]D51R\}VE
(ds*$]
public void run() jaTCRn3|<
{ m[5ed1+
while(nStartPos < nEndPos && !bStop) u<@ 55k
{ @[(%b{TE;
5OFb9YX
_i"[m(ABj1
try{ iow8H' F
URL url = new URL(sURL); (+\K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V[|k:($
httpConnection.setRequestProperty("User-Agent","NetFox"); <>1*1%m
String sProperty = "bytes="+nStartPos+"-"; z:$TW{%M
httpConnection.setRequestProperty("RANGE",sProperty); 4p&SlJ
Utility.log(sProperty); 9e1KH'
b~G|Bhxa
!P)7t`X
InputStream input = httpConnection.getInputStream(); 64!V8&Ay
//logResponseHead(httpConnection); xeHqC9Ou
gtP;Qw'
;/nR[sibN
byte[] b = new byte[1024]; > cJX'U9
int nRead; w3IU'(|G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E~!FEl;
{ esEOV$s}
nStartPos += fileAccessI.write(b,0,nRead); >G+?X+9
//if(nThreadID == 1) >7V&pH'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K31rt-IIt
} 1z(y>`ZBq
?G-a:'1!6
58My6(5y
Utility.log("Thread " + nThreadID + " is over!"); BPKeG0F7
bDownOver = true; *o[*,1Pw
//nPos = fileAccessI.write (b,0,nRead); )Nq$~aAm
} bsmnh_YRj
catch(Exception e){e.printStackTrace ();} M:(k7a+[^
} tL4xHa6v]
} gasl%&
SIRZ_lt$r
f;%4O'
//打印回应的头信息 akQtre`5sd
public void logResponseHead(HttpURLConnection con) 7[V'3
{ [OsW
for(int i=1;;i++) (#.)~poZ
{ nmN6RGx
String header=con.getHeaderFieldKey(i); z|yC[Ota
if(header!=null) b_=k"d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S*CRVs
Utility.log(header+" : "+con.getHeaderField(header)); 6i\b&
else fr\UX}o
break; M|`%4vk>
} p<6pmW3
} rC<m6
?Zoq|Q+
58MBG&a%
public void splitterStop() (F7!&]8%
{ }EOn=*
bStop = true; D1lHq/
} Hj;j\R >2
JX/rAnc@
3!CI=(^IY
} G#CWl),=
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=J?<M?ugf
/* <H E'5b
**FileAccess.java W?R$+~G
*//文件访问(定位，写) R{6.O+j`
package NetFox; )CXJRo`j0
import java.io.*; BbiBtU
y)#Ib*?
FAU^(]-5m
public class FileAccessI implements Serializable{ R_4600
it>FG9hVo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O*yc8fUI
RandomAccessFile oSavedFile; OBN]bvCJ
long nPos; [N#2uo
Yq) wE|k/
9[6*FAFJPP
public FileAccessI() throws IOException 8 s:sMU:Q
{ lcIX l&
this("",0); rMf& HX
} 8u;l<^<
eB!0:nHN
4"wuqr|o
public FileAccessI(String sName,long nPos) throws IOException G*Z4~-E4*
{ 0-4WLMx
oSavedFile = new RandomAccessFile(sName,"rw"); le|e 4f*+
this.nPos = nPos; i':<Ro
oSavedFile.seek(nPos); Z:9"7^+
} b\VY)=U
+l&ZN\@0X
Y@^MU->+
public synchronized int write(byte[] b,int nStart,int nLen) k9WihejS
{ ; >.>vLF
int n = -1; /_woCLwQ#
try{ ,uEWnZ"4
oSavedFile.write(b,nStart,nLen); {Sd{|R_
n = nLen; C8@SuJ
} T3)/?f?|
catch(IOException e) /[t]m,p$yq
{ 0sk*A0HX-
e.printStackTrace (); MBDu0 [c
} kUn55 l
-5d8j<,
3@s|tm1
return n; e [3sWv
} .v0.wG
m[Px|A5{
)5)S8~Oc
} SG;]Vr
pvP|.sw5G
p@NE^aMn
/* #U(dleT8
**SiteInfoBean.java Nx;U]O6A
*/ avykg(
package NetFox; Zz,E4+'Rm
RBJgQ<j8
hf8=r5j=
public class SiteInfoBean { :_i1)4[!
=MRg
70mQ{YNN
private String sSiteURL; //Site's URL kdITh9nx<r
private String sFilePath; //Saved File's Path [^P25K
private String sFileName; //Saved File's Name %#yCp2
private int nSplitter; //Count of Splited Downloading File D#1'#di*t
'kL>F&|
\ :1MM
public SiteInfoBean() [>oq~[e)?
{//nSplitter的缺省值为5 P+wV.pF|
//default value of nSplitter is 5 J,_I$* _0
this("","","",5); uqnoE;57^
} }>6=(!
b`PAOQ
S`5^H~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (SfP3
{ NELQo#kjZ
sSiteURL= sURL; Gyw@+(l
sFilePath = sPath; ~ 61O
sFileName = sName; 6cb;iA
this.nSplitter = nSpiltter; Aj*0nV9_
PBTGN;y
WhMr'l/e
} WXp=>P[
u7UqN
$C##S@
public String getSSiteURL() sf2_x>U1
{ {W62%>v
return sSiteURL; F=EAD3
} t7H2z}06=h
4^1{UlCop
R)?K+cJ%
public void setSSiteURL(String value) muwXzN(KX
{ #?k$0|60
sSiteURL = value; xC9^x7%3O
} :=+s^K
1uG?R
? }|;ai
public String getSFilePath() is}o5\JEL
{ mR,p?[P
return sFilePath; Wct +T,8
} |xG|HJm,
\7nlwFAO
"Q`{+|'=E
public void setSFilePath(String value) ^)m]j`}IGb
{ y,tA~
sFilePath = value; w;vp X>
} "!i7U2M'
z%Ywjfn'
8c\mm 0n
public String getSFileName() S U~vS
{ #IDDKUE
return sFileName; BA' ($D>
} *r!1K!c
dGAthbWJ
;TD<\1HJT=
public void setSFileName(String value) +V4BJ/H
{ AMA:hQ
sFileName = value; Ih!UL:Ckh
} ={ c=8G8T
<1.].A@b*
WM}:%T-
public int getNSplitter() %4Ylq|d
{ k[R/RhHQ,
return nSplitter; <~!7?ak
} cpz}!D
l]Jk }.
AGQCk*dm
public void setNSplitter(int nCount) Jg/l<4,K,
{ zNuiBLxDs
nSplitter = nCount; @g(N!n~
} + 1\1Z@\M
} 6*cm
g3 6oEz~|
z[b,:G
/* eft-]c+*0
**Utility.java @riCR<fF
*/ V:9|9$G
package NetFox; ?`_US7.@
h`Vb#5ik
.%+'Ts#ie
public class Utility { 9~I\WjB "
8)ZWR3)+W
d?GfT$1
public Utility() %h=)>5-T
{ ,w,>pO'[
AT}}RE@vq
xcnHj1r-o'
} F#7ZR*ZB1
w5gN8ZF3
//线程睡眠 10_eUQN
public static void sleep(int nSecond) m~1{~'
{ 'C+z
try{ JiEcPii
Thread.sleep(nSecond); iC?s`c0B
} DQP#h5O
catch(Exception e) 5u T 9ssC
{ g_G?gO
e.printStackTrace (); `J[(Dx'y=t
} q -M&f@Il
} @;qC% +^
~"\sL;B
//日志 0aQtJ0e16
public static void log(String sMsg) zT#36+_?
{ wYSvI
System.err.println(sMsg); !H{)L@f
} D;Fvd:
:^0g}8$<
2FD[D`n]f
public static void log(int sMsg) & d\`=e
{ z{d],M
System.err.println(sMsg); 6?Q&>V26Y
} QtJe){(z+
} auAST;"Z8
$5GvF1
)wP0U{7?v
/* ^%~ztn 51
**TestMethod.java s#`%c({U|
*/ [#V"a:8m}
package NetFox; Oh6;o1UI
k^Tu9}[W1
%2^C
public class TestMethod { ItDe_|!L
[POcO
@pQv}%
public TestMethod() $JqdI/s
{ ///xx/weblogic60b2_win.exe Yk(OVl T
try{ Tr)a6Cf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mvVVPf9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %83PbH
SiteFileFetch fileFetch = new SiteFileFetch(bean); yZHQql%J O
fileFetch.start(); 6NbIT[LvT
} H`-%)c=
catch(Exception e){e.printStackTrace ();} SjKIn-
bVtboHlY
^%M!!wlUH
} -2v|d]3qG
ZgtW
\4K8*`$
public static void main(String[] args) wC!(STu
{ cy)L%`(7
new TestMethod(); +hY/4Tx<
} HGWwGd
} AbZ:AJ(
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