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)); mgxoM|n6
} #}Qzu~
for(int i=0;i<nEndPos.length-1;i++) mOkf
{ 6*n<emP
nEndPos = nStartPos[i+1]; P:gN"f6
} zrg#BXj7
nEndPos[nEndPos.length-1] = nFileLength; _b8?_Zq
} 8I`t`C/4
} \Gk4J<
a*Oc:$
r)G^V&96
//启动子线程 tgPx!5U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y]SX2kk(2
for(int i=0;i<nStartPos.length;i++) {:;599l
{ *$I5_A8,.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D+ )R_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =E?!!EIq.
nStartPos,nEndPos,i); |E YJbL;1%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C\B&'+uR
fileSplitterFetch.start(); LK1 r@
} (79y!&9p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vxRy7:G"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^6E+l#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q{?ku!cL
nEndPos = " + nFileLength); V{j>09u
// fileSplitterFetch[nPos.length-1].start(); Gx]J6Z8
i]@QxzCSF
lj4D:>Ov
//等待子线程结束 H8g1SMT
//int count = 0; 1j7sJ" *
//是否结束while循环 ?/@~d
boolean breakWhile = false; ?{OB+f}Mo
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.%pbKi `
while(!bStop) d }"Dp
{ QKAo}1Pq
write_nPos(); Xo{|m[,
Utility.sleep(500); Gs% cod
breakWhile = true; =&J7 'nDP
>+ZG{'!j
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for(int i=0;i<nStartPos.length;i++) ;gC.fpu
{ l#W9J.q(
if(!fileSplitterFetch.bDownOver) q-g3!
{ $H9+>Z0(
breakWhile = false; b`=\<u8
break; _djr>C=H"
} vyt$
} *P#okwp
if(breakWhile) f"=1_*eH
break; s:6pPJL
5jTBPct
Aqwjs 3
//count++; ]+SVQ|v0
//if(count>4) /=5YHq>
// siteStop(); 8KQ]3Z9p
} >0W:snNK
o<hT/ P
u7oHqo`
System.err.println("文件下载结束！"); dsx'l0q 'i
} G8y:f%I!b
catch(Exception e){e.printStackTrace ();} YR2Q6}xR
} 1q])"l"<
<F=U(WWn9
Yy$GfjJtL]
//获得文件长度 Vd-\_VP20
public long getFileSize() b#:Pl`n6u
{ }E\ b_.
int nFileLength = -1; /$ -^k[%
try{ vakAl;
URL url = new URL(siteInfoBean.getSSiteURL()); b>B.3E\Pc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dc.oK4G}
httpConnection.setRequestProperty("User-Agent","NetFox"); '8Q:}{
1kG{z;9
jb!R
int responseCode=httpConnection.getResponseCode(); 6[dLj9 G%
if(responseCode>=400) Kd?TIeFE
{ G\y:O9(
processErrorCode(responseCode); &B</^:
return -2; //-2 represent access is error S}/?Lm}
} ;^q@w
*nv%~t
7gLN7_2
String sHeader; eVobs2s
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_Ra$"j
for(int i=1;;i++) Vt {uG
{ H8V${&!ho
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A/XY'3
//Utility.log(in.readLine()); 9!u=q5+E
sHeader=httpConnection.getHeaderFieldKey(i); jm_b3!J
if(sHeader!=null) E^:8Jehq
{ O>Vb7`z0<
if(sHeader.equals("Content-Length")) qP"+SVqC
{ %nTgrgS(=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _B@=fY(g!
break; g:l5,j.K
} )%4%Uo_Xm
} 6*] g)m
else HC4vet
break; Svs!C+:le
} Osb#<9{}
} :u%Jrc(W
catch(IOException e){e.printStackTrace ();} 4,8=0[eRG
catch(Exception e){e.printStackTrace ();} kEH(\3,l
h|=<I)}z
j4ARGkK5B
Utility.log(nFileLength); qUH02"z@9
bbDl?m&bq
GOT@
return nFileLength; (v11;kdJB
} WOW:$.VO^
W| z djb
Zc_%hQf2A
//保存下载信息（文件指针位置） i8F^ N=
private void write_nPos() Hm>M}MF3
{ Z/#&c
try{ u&q RK>wLa
output = new DataOutputStream(new FileOutputStream(tmpFile)); .?L&k|wX-
output.writeInt(nStartPos.length); <oweLRt
for(int i=0;i<nStartPos.length;i++) C #A sA
{ $\S;f"IM.
// output.writeLong(nPos); .AIlv^:|U
output.writeLong(fileSplitterFetch.nStartPos); Htg,^d 5
output.writeLong(fileSplitterFetch.nEndPos); O]"3o,/]G
} =J2\"6BnzA
output.close(); :ET05MFs\#
} cR/-FR
catch(IOException e){e.printStackTrace ();} Pc+8CuN?
catch(Exception e){e.printStackTrace ();} mVJW"*}8
} 1o&]=(
IFrq\H0
f`zH#{u
//读取保存的下载信息（文件指针位置） Q.3oDq
private void read_nPos() Q&zEa0^rG6
{ ^6tcB* #A
try{ CdxEY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4eZ
int nCount = input.readInt(); &d"c6il[
nStartPos = new long[nCount]; [(Z sQK
nEndPos = new long[nCount]; T=/GFg'
for(int i=0;i<nStartPos.length;i++) f}jo18z%
{ 'hTAO1n8
nStartPos = input.readLong(); s:_M+_7_
nEndPos = input.readLong(); 6`/nA4S4.
} E5-f{Qc
input.close(); 4NY00d/R
} vx:MLmZ.
catch(IOException e){e.printStackTrace ();} @8IYJ{=
catch(Exception e){e.printStackTrace ();} tY?_#rc
} (7C&I-l
gmU_# J%~
h/I'9&J>*
private void processErrorCode(int nErrorCode) wz!a;]agg
{ ^tWt"GgC
System.err.println("Error Code : " + nErrorCode); udRum7XW3
} u/`jb2eEU:
aNZJs<3;'D
3kAmRU
//停止文件下载 yv.Y-c=
public void siteStop() m!{}Y]FZn
{ cY%[UK$l
bStop = true; c\X0*GX
for(int i=0;i<nStartPos.length;i++) 'dE G\?v9
fileSplitterFetch.splitterStop(); S >E|A%
SJ1 1LF3)
>V:g'[b
} 2-821Sf#h
} \(_FGa4j
//负责部分文件的抓取 >LxYP7M
**FileSplitterFetch.java }S6Sz&)
*/ 2Mx9Kd'a r
package NetFox; +r)'?zU
W(9fCDO;
ToIvyeFr
import java.io.*; a pqzf
import java.net.*; $3](6
GW$(E*4q
v%3mhk#
public class FileSplitterFetch extends Thread { 89KX.d
P[PBoRd2
>`DbT:/<
String sURL; //File URL ]X+3"
long nStartPos; //File Snippet Start Position 5J1A|qII
long nEndPos; //File Snippet End Position b7>^w<ki
int nThreadID; //Thread's ID E)|_7x<u
boolean bDownOver = false; //Downing is over <^VZ4$j
boolean bStop = false; //Stop identical P8.tl"q
FileAccessI fileAccessI = null; //File Access interface "HFS5Bj'
+M%i3A
yEt:g0Z\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,-Fhb~u
{ i> Ssp
this.sURL = sURL; G~T]m .
this.nStartPos = nStart; p~M1}mE
this.nEndPos = nEnd; fAWjk&9
nThreadID = id; }NPF]P;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 We3*WsX\
} GqhnE>
Y?hC/6$7
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public void run() B?c9cS5Mj
{ ITh1|yP
while(nStartPos < nEndPos && !bStop) haW8zb0z
{ z<rdxn,9
pmXx2T#=
wzB*M}3
try{ S4kGy}{+i
URL url = new URL(sURL); 9z5K -s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $DW3H1iW
httpConnection.setRequestProperty("User-Agent","NetFox"); fXMVl\ <
String sProperty = "bytes="+nStartPos+"-"; QOIi/flK
httpConnection.setRequestProperty("RANGE",sProperty); 9@C3jZ+9`H
Utility.log(sProperty); $enh>!mU
u4B,|_MK
*!UY;InanX
InputStream input = httpConnection.getInputStream(); 5=Mm=HyI2
//logResponseHead(httpConnection); WMBntB
<Fb3\T L
70&v`"
byte[] b = new byte[1024]; 13Ga #
int nRead; eN{[T PPCq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hb9X<N+p
{ 8%JxXtWW`
nStartPos += fileAccessI.write(b,0,nRead); (5{|']G
//if(nThreadID == 1) o#E 3{zM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mnL \c'
} 1Nx.aji
vTjgW?9
R|H9AM ~E
Utility.log("Thread " + nThreadID + " is over!"); "!XeK|Wi
bDownOver = true; m}0US;c#f
//nPos = fileAccessI.write (b,0,nRead); OlhfBu)~
} PRl\W:_t
catch(Exception e){e.printStackTrace ();} +O3zeL
} =25qY"Mf
} ?RvXO'ml
VE^NSkOa&
_:0<]<x?
//打印回应的头信息 }5bh,'
public void logResponseHead(HttpURLConnection con) 7P9n. [
{ 1Nw&Z0MI
for(int i=1;;i++) ?UQVmE&
{ ^4]#Ri=U
String header=con.getHeaderFieldKey(i); *x[B g]/
if(header!=null) N+l~r]: &
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0.O pgv2K
Utility.log(header+" : "+con.getHeaderField(header)); JY0t Hs
else Y+<C[Fiq
break; X`]-)(UX
} G;V@oT
} _~_04p
oT&JQ,i[2Q
wRb%-s
public void splitterStop() QRdNi1&M
{ BHn`e~
bStop = true; #h ;j2
} #NNj#
F/ 2@%,2n
p+;Re2Uyg
} 1O45M/5\o
93x.b]]"
!$AVlMnJ
/* J"|)?$d]z
**FileAccess.java r\vB-nJ
*//文件访问(定位，写) K7<'4i~k
package NetFox; jd l1Q<Z
import java.io.*; =nFT0];
nSsVONHfa
H#k"[eZ
public class FileAccessI implements Serializable{ 9 f-T>}
swG^L$r`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xj{X#[q):
RandomAccessFile oSavedFile; "Na9Xea
long nPos; v6oPAqj,r
riZFcVsB
G6JyAC9j
public FileAccessI() throws IOException Q'JEDH\
{ /}2 bsiJT
this("",0); 0NfO|l7P
} )]J I Q"rR
5h1!E
Y:^ =jV7
public FileAccessI(String sName,long nPos) throws IOException !W^2?pqN
{ _4o2AS:j
oSavedFile = new RandomAccessFile(sName,"rw"); 2F!K }aw
this.nPos = nPos; Y@KZ:0<
oSavedFile.seek(nPos); nX5*pTfjL3
} &Xe r#6~
tA#X@HIE
p$f#W
public synchronized int write(byte[] b,int nStart,int nLen) 'nP'MA9b;a
{ ^K@r!)We
int n = -1; 6\ux;lksn*
try{ vc6UA%/f
oSavedFile.write(b,nStart,nLen); tt[P{mMQ
n = nLen; [2 2IF
} ="@W)"r
catch(IOException e) 1?(BWX)7
{ Qu!\Cx@
e.printStackTrace (); ZyCAl9{p
} P.qD,$-
{,IWjt &>
?MKf=!w
return n; P)1@HDN==
} 2@08V|
`"AjbCL
f*XF"@ZQV
} z$7YC49^
Ez?vJDd
:FG}k Y
/* Q)#<T]~=
**SiteInfoBean.java C>v
*/ k%hD<_:p
package NetFox; {Hp?rY@
kjNA~{
Zt lS*id_
public class SiteInfoBean { ]|u}P2
"oz@w'rG
7;CeQx/W)W
private String sSiteURL; //Site's URL [2i+f<
private String sFilePath; //Saved File's Path `Z|sp
private String sFileName; //Saved File's Name G8u8&|
private int nSplitter; //Count of Splited Downloading File y{u6t 3
eoEb\zJ
ujz %0Mq;
public SiteInfoBean() + W@r p#
{//nSplitter的缺省值为5 Z6D4VZVF
//default value of nSplitter is 5 ^{6Y7T]
this("","","",5); FT|*~_@
} iM8hGQ`
zNE!m:s
W**=X\"'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .kC}. Q_
{ /@3+zpaw X
sSiteURL= sURL; #H!~:Xu
sFilePath = sPath; (R6ZoBZ
sFileName = sName; S<Q1 &],
this.nSplitter = nSpiltter; <(f4#BP
4T^M@+&|
jQb=N%5s
} GK&yP%Z3
So`xd *C!
@b>]q$)(}
public String getSSiteURL() 5&}icS
{ {_q2kk
return sSiteURL; 46XB6z01
} N23s{S t
}rO4b>J
XX6&%7(
public void setSSiteURL(String value) 7PQedZ<\
{ @=;6:akz`
sSiteURL = value; yLDHJ}R
} ,7j`5iq[m
fx;5j;
r#Pd@SV
public String getSFilePath() ..~{cU4Tt
{ z? {#/
return sFilePath; z9D2,N.
} whLske-
s &.Z;X
il#rdJ1@t
public void setSFilePath(String value) e<p$Op
{ _Jp_TvP>
sFilePath = value; 2f:'~ P56
} ItRGq
'R'>`?Nh
4U6{E#
public String getSFileName() RtIc:ym
{ 9723f1&Vd
return sFileName; {>+$u"*
} 5vpf;
RU{}qPs?
1B1d>V$*
public void setSFileName(String value) RF;N]A?*
{ yjSN;3t71
sFileName = value; `2@-'/$\I|
} ?DRC! 9o^
Ee|@l3)
>N,G@{FR
public int getNSplitter() CD[7h
{ *jJ62-o
return nSplitter; VLO>{"{'
} :?p{ga9
p0tv@8C>
v4v+;[a%
public void setNSplitter(int nCount) \;?\@vo<
{ t{7l.>kf
nSplitter = nCount; JNu- z:J
} S1B/ClKWq
} m_Rgv.gE^
HAiUFO/R
TtvS|09p;
/* E$1^}RGT)
**Utility.java 9:Y:Vx
*/ [%@zH
package NetFox; cr/|dc'
H 0h
^s?wnEo;j
public class Utility { O[`Ob6Q{F
>ciq4H43Q|
:rj78_e9
public Utility() 7'8O*EoB'
{ -m@s 9k
1]<!Xuk^f
C{ti>'"V
} x)?\g{JH
ms{R|vU%b
//线程睡眠 oF>GWstTR
public static void sleep(int nSecond) E??%)q
{ e"2QV vB
try{ FjydEV
Thread.sleep(nSecond); #<~f~{x
} F9<OKcXH
catch(Exception e) Cn55%:
{ NV gLq@F
e.printStackTrace (); 9=o b:
} N\fT6#5B
} Lg?'1dg
' EDi6
//日志 Jt)~h,68
public static void log(String sMsg) <2Q@^
{ Y/^<t'o&
System.err.println(sMsg); \fhT#/0N
} toWmm(7v
ZX0c_Mk=
j{^(TE
public static void log(int sMsg) +doT^&2u*
{ /'1y`j<
System.err.println(sMsg); v<SEGv-
} IBqY$K+l
} /OP*ARoC21
'l:2R,cP
}"-r;i
/* |rvrSab)
**TestMethod.java c|R/,/
*/ jQb D2x6(
package NetFox; 9PJDT]
9X%Klm 5w
[z~Nw#
public class TestMethod { K[[k,W]qb
.ndQ(B
LC{hoq\
public TestMethod() FNuu',:
{ ///xx/weblogic60b2_win.exe 2X*<Fma3C
try{ X{ =[q|P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =5`@:!t7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /)1-^ju
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q8x{V_Pot
fileFetch.start(); a%!XLyq
} ^{s0d+@{
catch(Exception e){e.printStackTrace ();} ~Z2eQx jtM
=dBrmMh
HWhKX:`l
} a,~P_B|@
m'tk#C
50&F#v%YB
public static void main(String[] args) +][P*/Ek
{ $at|1+bQ
new TestMethod(); udFju&!W
} \DqxS=o;
} vI'>$
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