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)); wQ /IT}-
} &~of]A
for(int i=0;i<nEndPos.length-1;i++) @sUYjB
{ +eSNwR=
nEndPos = nStartPos[i+1]; %UDz4?zx
} o2
nEndPos[nEndPos.length-1] = nFileLength; XKD0n^L[
} h.PVRAwk
} `)Z"||8K
J jRz<T;
f%fD>a
//启动子线程 2Wwzcvs@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @v^;,cu'8
for(int i=0;i<nStartPos.length;i++) -`nQa$N-
{ xE.K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NUBf>~_}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |[apLQ6
nStartPos,nEndPos,i); *->2$uWP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $+CKy>
fileSplitterFetch.start(); hTZ&
} %M8m 8 )
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7kX;|NA1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UnSi=uj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q`1"]gy.
nEndPos = " + nFileLength); \1Tu P}P
// fileSplitterFetch[nPos.length-1].start(); KY5it9e
`@%hz%8Y
B:Y"X:Y
//等待子线程结束 iNj*Gj
//int count = 0; g\_J
//是否结束while循环 DFDlp
boolean breakWhile = false; a;a^- n|D
T1,Nb>gBq^
m)"gj**|y
while(!bStop) Jbv66)0M
{ cAFYEx/(
write_nPos(); SU>2MT^
Utility.sleep(500); /4Ud6gscf
breakWhile = true; *AK{GfP_
]fxYSm
!1G6ZC:z
for(int i=0;i<nStartPos.length;i++) L@9@3?
{ @JB9qT
if(!fileSplitterFetch.bDownOver) HRQ3v`P.
{ G8bc\]
breakWhile = false; RuyqB>[o
break; 'W'['TV
} 9)P-<
} "[A]tklP
if(breakWhile) `"@Pr,L
break; @8\7H'K"\
X#v6v)c
}eKY%WU>O
//count++; TS2zzYE6Z
//if(count>4) ;iA6[uz
// siteStop(); )W,tL*9[
} m9~cQ!m
6:\0=k5
PB[Y^q
System.err.println("文件下载结束！"); a-[:RJW
} B\WIoz;'
catch(Exception e){e.printStackTrace ();} \%],pZsA~
} tW$Di*h
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wE*o1.
//获得文件长度 9NXL8QmC8
public long getFileSize() 2TQyQ%
{ :8( "n1^
int nFileLength = -1; `^d[$IbDW
try{ hCpX#rg?
URL url = new URL(siteInfoBean.getSSiteURL()); nDG41)|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {$ a $m
httpConnection.setRequestProperty("User-Agent","NetFox"); -_`dA^
X(r$OZ
`1xJ1z#
int responseCode=httpConnection.getResponseCode(); vZ6_/ew8
if(responseCode>=400) Al93x
{ e-&0f);i
processErrorCode(responseCode); |.]g&m)y^h
return -2; //-2 represent access is error &];:uYmMU
} T)CEcz
5~ip N/)E
}Bk>'
String sHeader; @#u'z~a)
:`Sd5b>
+HAd=DU
for(int i=1;;i++) []L yu
{ QmiS/`AAv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XEX-NE"]
//Utility.log(in.readLine()); 7Be\^%
sHeader=httpConnection.getHeaderFieldKey(i); I_.Jo `lK~
if(sHeader!=null) qI=j>x
{ Q[6<Y,}(pd
if(sHeader.equals("Content-Length")) PR+L6DT_
{ 7my7|s[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UngK9uB~
break; ~;AJB
} v)c[-:"z
} ]ykMh
else =w,cdU*
break; ^X\{MW'>4
} 1b``y
} d,V]j-
catch(IOException e){e.printStackTrace ();} RCC~#bb
catch(Exception e){e.printStackTrace ();} bnZ`Wc*5b
Au"7w=G`f
C@F3iwTtp
Utility.log(nFileLength); (~U1X4
'Dx_n7&=
#cCR\$-~
return nFileLength; <jz\U7TBf
} be+]kp
yN/Uyhq
i w(4!,4~
//保存下载信息（文件指针位置） b^dBX
private void write_nPos() 9zKbzT]
{ nW"ml$
try{ sry`EkS
output = new DataOutputStream(new FileOutputStream(tmpFile)); Om,M8!E
output.writeInt(nStartPos.length); 5^0K5R6GQf
for(int i=0;i<nStartPos.length;i++) *.P3fVlZ
{ (X|`|Y
// output.writeLong(nPos); S(NUuu}S
output.writeLong(fileSplitterFetch.nStartPos); VT:m!<^
output.writeLong(fileSplitterFetch.nEndPos); b&g`AnYT
} kN8?.V%Utw
output.close(); x7!YA>
} m&I5~kD
catch(IOException e){e.printStackTrace ();} wK*b2r}0/
catch(Exception e){e.printStackTrace ();} 0(h'ZV
} egHvI&w"o
n[c/L8j
&{=`g+4n
//读取保存的下载信息（文件指针位置） V|T3blG?D
private void read_nPos() ~=Q|EhF5
{ p}K\rpvJpu
try{ $ 0Up.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -Izc-W
int nCount = input.readInt(); W^T6^q5;H
nStartPos = new long[nCount]; Hphfqdh0`
nEndPos = new long[nCount]; Ks/Uyu. X
for(int i=0;i<nStartPos.length;i++) G ]JWd
{ IA(+}V
nStartPos = input.readLong(); A1kqWhg\
nEndPos = input.readLong(); l ]CnLqf&
} 2nv-/%]
input.close(); #Py\'
} y^tp^
catch(IOException e){e.printStackTrace ();} \?K>~{)
catch(Exception e){e.printStackTrace ();} 5Vu@gRk_
} a"pejW`m
15U[F0b
>&DNxw
private void processErrorCode(int nErrorCode) k_A 9gj1
{ 0o*
System.err.println("Error Code : " + nErrorCode); ;Y"*Z2U
} f%ynod8
<f/wWu}
n%%u0a%
//停止文件下载 FZJyqqA$_
public void siteStop() 38HnW
{ 6JZ$;x{j
bStop = true; 6~y7A<[^
for(int i=0;i<nStartPos.length;i++) w@Gk#
fileSplitterFetch.splitterStop(); :d`8:gv?
KGq4tlM6
P6([[mmG
} 3^%sz!jK+
} h8-'I=~
//负责部分文件的抓取 )WR*8659e
**FileSplitterFetch.java {WYmO1
*/ c:f++||
package NetFox; =F>nqklc
GTBT0$9g.
x}*Y =Xh
import java.io.*; vo3[)BDbT
import java.net.*; -7\6j#;l
;DN:AgXP
OK1f Y`$z
public class FileSplitterFetch extends Thread { /&Vgo~.J
a"|\n_
u*C"d1v=
String sURL; //File URL C~([aH@-I
long nStartPos; //File Snippet Start Position ab-MEN`5
long nEndPos; //File Snippet End Position *d/,Y-tl
int nThreadID; //Thread's ID |=U(8t
boolean bDownOver = false; //Downing is over /@~&zx&_
boolean bStop = false; //Stop identical y+D"LeCAad
FileAccessI fileAccessI = null; //File Access interface 3V2w1CERE
j"Vb8}
$v*0\O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YTo^Q&
{ ;rJ
this.sURL = sURL; 9X[}ik0
this.nStartPos = nStart; y+ZCuX
this.nEndPos = nEnd; q=|0lZ$`V_
nThreadID = id; R404\XGL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sxBRg=
} Hz] p]
DJ#z0)3<p
{Vj25Gt
public void run() DZ9qIc}Y
{ TV&4m5
while(nStartPos < nEndPos && !bStop) {aRZBIv
{ Vy:MK9U2
$xsmF?Dsx5
QW_QizR>|
try{ *E-VS= #
URL url = new URL(sURL); K`d3p{M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :.,3Zw{l
httpConnection.setRequestProperty("User-Agent","NetFox"); 3ZKaqwK
String sProperty = "bytes="+nStartPos+"-"; xK8R![x
httpConnection.setRequestProperty("RANGE",sProperty); S3(2.c~
Utility.log(sProperty); >|e>=
9v2(cpZ
\p&a c&]
InputStream input = httpConnection.getInputStream(); }:5>1FfX=
//logResponseHead(httpConnection); ;*8nd-\
!Ho=(6V
D;l)&"|r?
byte[] b = new byte[1024]; LN?b6s75U
int nRead; ^MZdht
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9+sOSz~ P
{ k-M-=VvA
nStartPos += fileAccessI.write(b,0,nRead); LpJ_HU7@lk
//if(nThreadID == 1) $*u{i4b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Gr775"
} ,UD,)ZPf[
J&IFn/JK$
G3G"SJ np
Utility.log("Thread " + nThreadID + " is over!"); }813.U
bDownOver = true; 8/|~E
//nPos = fileAccessI.write (b,0,nRead); oQvG3(.
} #(`@D7S"
catch(Exception e){e.printStackTrace ();} h""a#n)q}`
} @e/40l|X
} G)E#wh_S^
Y}C~&Ph
x_3Zd
//打印回应的头信息 $]05?JY#
public void logResponseHead(HttpURLConnection con) Wo^r#iRko
{ q&-A}]
for(int i=1;;i++) $ZPiM
{ Yjr6/&ML
String header=con.getHeaderFieldKey(i); `[+nz rLkO
if(header!=null) y/}>)o4Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]o(&J7Z6-
Utility.log(header+" : "+con.getHeaderField(header)); AwKxt'()^
else t*? CD.S
break; t: =
} "lp),
} fi[c^e+IX
O_p:`h:;M
oR=^NEJv
public void splitterStop() Q1Jkt
{ :q2tda
bStop = true; cJ%u&2J_
} .+H8c.
V^t5 Y+7
s1!_zf_
} @ P=eu3
ezt_ct/Z
#@m*yJg<
/* d`|W6Do
**FileAccess.java %KeQp W
*//文件访问(定位，写) G~{xTpL
package NetFox; \Mv8pU
import java.io.*; ;n*N9-|.
O/IW.t
V;Zp3Qo!
public class FileAccessI implements Serializable{ fNi&1J-/
Hy<4q^3$G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ] =jnt
RandomAccessFile oSavedFile; 3:rH1vG.m
long nPos; j/bebR}X
sBuVm<H
g#V3u=I8~
public FileAccessI() throws IOException d0b--v/
{ 2O|o%`?
this("",0); FxKb
} (WK$ )f
[UI4YZu}
=*q:R9V
public FileAccessI(String sName,long nPos) throws IOException eB:obz
{ -K`0`n}
oSavedFile = new RandomAccessFile(sName,"rw"); .~a)
this.nPos = nPos; %8kbX
oSavedFile.seek(nPos); Y"mD)\Bw?
} ,>%AEN6N2
3:a}<^DuCS
]D7z&h
public synchronized int write(byte[] b,int nStart,int nLen) B{W2D
{ j=)%~@
int n = -1; PZ-|W
try{ %HuQc^
oSavedFile.write(b,nStart,nLen); g S;p::
n = nLen; 4];Qpln
} b9(d@2MtK
catch(IOException e) HLAYmXX"w
{ #UC4l]Ru A
e.printStackTrace (); &_&])V)<\S
} dCcV$BX,K
Yuze9b\[
"2CiW6X[M
return n; <W vuW6
} :*1Gs,
pM\)f
1uv"5`%s
} =[`wyQe`_
#JZf]rtp
+=MO6}5T
/* 6.~(oepu
**SiteInfoBean.java oC U8;z
*/ ~sAINV>A
package NetFox; M!=v"C#
P-No;/!B#
AY0o0\6cw
public class SiteInfoBean { 5Zn3s()
F& H~JJ
RgQ\Cs24Q
private String sSiteURL; //Site's URL W1y,.6
private String sFilePath; //Saved File's Path 5cyl:1Ln
private String sFileName; //Saved File's Name U*k$pp6\b~
private int nSplitter; //Count of Splited Downloading File I_#)>%H
7 m&M(ct
WLNkO^zb
public SiteInfoBean() ^gkyi/z
{//nSplitter的缺省值为5 b]RnCu"
//default value of nSplitter is 5 u|8`=
this("","","",5); pa+^5N
} h+.^8fPR
/Rk5n
3Luv$6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Um15@p;
{ :!tQqy2
sSiteURL= sURL; gNs@Q!
sFilePath = sPath; 1 EC0wX
sFileName = sName; I U4[}x
this.nSplitter = nSpiltter; ":"M/v%F
sNX$ =<E
=q5A@!D
} G!OD7:
)KBv[|
FNmIXpAn*@
public String getSSiteURL() <`|}bt
{ K~,,xsy,G&
return sSiteURL; o?p) V^7
} }tv-
gMI%z2]'-
B7}-g"p$/
public void setSSiteURL(String value) ,{8~TVO
{ 9KXp0Q?-$
sSiteURL = value; w=#&(xm0
} {Fb)Z"8]
,*S?L qv^
#wM0p:<
public String getSFilePath() |.(o4<nx.
{ {,s:vPoiA
return sFilePath; W11_MTIU
} >454Yir0Mk
Jz%&-e3
~`-9i{L
public void setSFilePath(String value) p2&KGtX'
{ 4f"be
sFilePath = value; 3\mFK$#sr
} >%[(C*Cks
V!},a@>p
rKJ%/7m
public String getSFileName() -Qn:6M>w^
{ sUbZVPDr
return sFileName; $AsM 9D<BE
} )2^OBfl7
=C#,aoa!
qM1$?U
public void setSFileName(String value) ]E=JUYf0
{ })!n1kt
sFileName = value; ]"CAP%
} jsez$m%vs
M $e~Rlw
bQ .y,+
public int getNSplitter() {5%<@<?)
{ 3!}'A
return nSplitter; jH:*x$@ =
} )Fm
1km=9[;w'
YKM(qh2
public void setNSplitter(int nCount) B:x4H}`vh
{ HPpnw]_
nSplitter = nCount; dc5B#
} n$=n:$`q
} w[|!$J?
<M\Z}2d
=lDmP|^
/* ,bH
**Utility.java *i$+i
*/ 3(PU=
package NetFox; ,5L&$Q6
<XLATS8Y
GzR;`,_O/
public class Utility { O:Z|fDQ`
f%|g7[
@wa/p`gj5w
public Utility() hQet?*diU
{ nwkhGQ
UHCx}LGe
_@RW7iP>
} A!^,QRkRN
'Uc|[l]
//线程睡眠 'Klz`)F
public static void sleep(int nSecond) };KmMpBn
{ (PB|.`_<H
try{ f'.yM*
Thread.sleep(nSecond); 4Fz^[L}[
} dm 2_Fj
catch(Exception e) >i ~zG6H
{ /3c1{%B\
e.printStackTrace (); }=L >u>cP
} HL!-4kN <$
} #/1Bam6
ca`=dwe>
//日志 woR)E0'qx
public static void log(String sMsg) &#)3v8
{ x*)Wl!
System.err.println(sMsg); r8> q*0~s
} "vJADQ4F
8uu:e<PLv
Uexb>|
public static void log(int sMsg) v>e4a/
{ JBg>E3*N
System.err.println(sMsg); {:dE_tqo
} >/n/n{{
} LTCjw_<7
lWdE^-
A} "*`y
/* F 4hEfO3
**TestMethod.java D\TL6"wo
*/ :V"}"{(6
package NetFox; $C>EnNx
9Z*vp^3
!XicX9n
public class TestMethod { !hc7i=V?
f[v??^
jc?Hip'
public TestMethod() 4 I~,B[|
{ ///xx/weblogic60b2_win.exe f9rToH
try{ uu/MXID
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B\mdOTLQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PNG'"7O
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8[Qw8z5-
fileFetch.start(); xv ja
} w_Ls.K5"
catch(Exception e){e.printStackTrace ();} 0$ (}\hMLt
J'7Oxjlg
m$ JQ[vgh
} jC@^/rMh
TwkzX|
5_O.p3$tV
public static void main(String[] args) eu4x{NmQ
{ ewLr+8
new TestMethod(); V?gQ`( ,
} [ wROIvV
} $M8'm1R9
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