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)); xU:PhhS
} l,ZzB,"
for(int i=0;i<nEndPos.length-1;i++) 7?)m(CFy
{ xXl$Mp7
nEndPos = nStartPos[i+1]; YL_!#<k@
} ok8JnQC
nEndPos[nEndPos.length-1] = nFileLength; I]s:Ev[~
} !<JG&9ODP
} t"4Rn<-
oo"JMD)
,|=iv
//启动子线程 s#4))yUR6Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c|8KT
for(int i=0;i<nStartPos.length;i++) 9p!dQx
{ 0^_)OsFA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m^(E:6T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bt.K<Y0
nStartPos,nEndPos,i); +/1P^U /
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r5<e}t-
fileSplitterFetch.start(); &ij^FAM
} #0#V$AA>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xQcMQ{&;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "y3dwSS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oQKcGUZ
nEndPos = " + nFileLength); ,(5dQ`hA0
// fileSplitterFetch[nPos.length-1].start(); Qt)7mf
H>Iet}/c
NiU tH
//等待子线程结束 @vDgpb@TM
//int count = 0; xf{C'uF/
//是否结束while循环 cPa 0n4
boolean breakWhile = false; >(YPkmH
d60Fi#3d
`"1{Sx.
while(!bStop) I NFzX
{ ()rx>?x5
write_nPos(); +"fM &F]
Utility.sleep(500); G> 5=`
breakWhile = true; 7m@^=w
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'44nk(hM69
for(int i=0;i<nStartPos.length;i++) 9#.NPfMF
{ FK/ro91L
if(!fileSplitterFetch.bDownOver) "|~B};|MFF
{ UO7a}Tz<
breakWhile = false; kcZ;SYosj
break; fQ?n(
} [b\lcQ8O
} eUUD|U*b
if(breakWhile) ?yd(er<_f
break; 5)o-]S>
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D;T r
//count++; 8-l)TTP&.
//if(count>4) O7#}8-@}<u
// siteStop(); |SXMu_w
} VHY<(4@
,:Ix s^-
C">=2OO
System.err.println("文件下载结束！"); w[$Wpae
} :Y)kKq d
catch(Exception e){e.printStackTrace ();} ![MDmt5Ub^
} ~IN$hKg^
Vp0GmZ
H?r;S 5)c
//获得文件长度 m3v*,~
public long getFileSize() Up2\X#6
{ T`2fPxM:cZ
int nFileLength = -1; do?n /<@o
try{ ?jM7C}
URL url = new URL(siteInfoBean.getSSiteURL()); 0?*I_[Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q)|LiCR,
httpConnection.setRequestProperty("User-Agent","NetFox"); !NY^(^
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int responseCode=httpConnection.getResponseCode(); ^OcfM_4pN
if(responseCode>=400) 6+d"3-R.
{ $T%<'=u|E
processErrorCode(responseCode); "5DAGMU
return -2; //-2 represent access is error KD3To%
} rL+n$p X-
hFPRC0ftE
QNI|h;D
String sHeader; D/6@bcCSY
tMk>Bx9[
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for(int i=1;;i++) [/,6O
{ g~sNY|%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KI QBY!N+
//Utility.log(in.readLine()); :/[ZgreN6
sHeader=httpConnection.getHeaderFieldKey(i); JfINAaboi
if(sHeader!=null) FG36,6N%2j
{ `1v!sSR0R
if(sHeader.equals("Content-Length")) *R6eykp
{ xR6IXF>*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wn#JYp
break; p. ~jo
} `A{~}6jw
} v#2qwd3x
else ]4~D;mv
break; Id 7
} 2EcYO$R!
} CN>};>WlG
catch(IOException e){e.printStackTrace ();} `i^1U O
catch(Exception e){e.printStackTrace ();} rBPxGBd4
)g<qEyJR
KgAX0dM
Utility.log(nFileLength); WbzL!zLd!
DL!s)5!M
o%4+I>
return nFileLength; O5*uL{pvT{
} 7B2Og{P
5|t&qUV
5DUPsV
//保存下载信息（文件指针位置） XdVC>6
private void write_nPos() =gyK*F(RK
{ LtIZgOd<
try{ sb5kexGxkc
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4/vQ=t
output.writeInt(nStartPos.length); uCr
for(int i=0;i<nStartPos.length;i++) 'Em($A(
{ nu-wQr
// output.writeLong(nPos); >n\Q[W
output.writeLong(fileSplitterFetch.nStartPos); %LW~oI.
output.writeLong(fileSplitterFetch.nEndPos); @V u[Tg}J
} z<=t3dj
output.close(); Bv*h?`Q
} ]`m5!V_Y
catch(IOException e){e.printStackTrace ();} I2Q?7p
catch(Exception e){e.printStackTrace ();} '|r!yAO6
} j* ?MFvwE
YI+|6s[
<O&s 'A[
//读取保存的下载信息（文件指针位置） % m$Mnx
private void read_nPos() A 76yz`D
{ %"V,V3kw4
try{ oLRio.u*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i:To8kdO
int nCount = input.readInt(); }c:0cl
nStartPos = new long[nCount]; eU*hqy?0
nEndPos = new long[nCount]; K~G^jAk+
for(int i=0;i<nStartPos.length;i++) ?~8V;Qn
{ dksnW!
nStartPos = input.readLong(); 2x CGr>X
nEndPos = input.readLong(); .kV/0!q?
} !).dc.P
input.close(); iLei-\w6y
} Jr zU-g
catch(IOException e){e.printStackTrace ();} mmti3Y
catch(Exception e){e.printStackTrace ();} @m4d4K@
} 5@\<:Zmi
+q!6zGs.
oizoKwp%
private void processErrorCode(int nErrorCode) cA,xf@itp
{ 4`B:Mq&j
System.err.println("Error Code : " + nErrorCode); ygG9ht
} F u)7J4Z
~$<@:z{*
DzMkeX
//停止文件下载 qm_\#r
public void siteStop() YjT #^AH
{ ,KWeW^z'7
bStop = true; TDFv\y}yc
for(int i=0;i<nStartPos.length;i++) ~j_H2+!
fileSplitterFetch.splitterStop(); F);C?SW"
-\vq-n
'=5N?)
} u Wtp2]A
} hsh W5j
//负责部分文件的抓取 %"tf`,d~3
**FileSplitterFetch.java #i?TCO
*/ V=U%P[S
package NetFox; &yuerNK
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pc #^{-
import java.io.*; `|4{|X*U.
import java.net.*; - >2ej4C
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BFY~::<b
public class FileSplitterFetch extends Thread { K)n(U9#
X~0P+E#
mcvTz, ;=
String sURL; //File URL DWDe5$^{
long nStartPos; //File Snippet Start Position rW6LMkt72
long nEndPos; //File Snippet End Position m@~HHwj
int nThreadID; //Thread's ID d-4u*>
boolean bDownOver = false; //Downing is over !Lo{zTDW
boolean bStop = false; //Stop identical jU=)4nx
FileAccessI fileAccessI = null; //File Access interface D:f#
0kDT:3
Jv5G:M5+~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9P]TIV.
{ $iV3>>;eh
this.sURL = sURL; W[b/.u5z:
this.nStartPos = nStart; `g#\ Ws
this.nEndPos = nEnd; Z]aSo07
nThreadID = id; i^=an?}/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U+W8)7bc
} zMDR1/|D
79&Mc,69
=%bc;ZUu
public void run() W1#3+
{ P9c1NX\-
while(nStartPos < nEndPos && !bStop) /(Y\ <
{ T_r[#j
n4"xVDL
RJN LcIm
try{ ,s@S`KS0
URL url = new URL(sURL); Hb^ovc0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s <$*A;t
httpConnection.setRequestProperty("User-Agent","NetFox"); ,d=Dicaz
String sProperty = "bytes="+nStartPos+"-"; jt9@aN.mJN
httpConnection.setRequestProperty("RANGE",sProperty); q^@*k,HG
Utility.log(sProperty); *s2 C+@ef
{gDoktC@M
[{ A5BE -
InputStream input = httpConnection.getInputStream(); sP8_Y,
//logResponseHead(httpConnection); gJ$m'kC;
_.,"`U; H
!#WJ(zSq
byte[] b = new byte[1024]; gvP.\,U
int nRead; -#AO4xpI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o 7&q
{ R_:-Z.
nStartPos += fileAccessI.write(b,0,nRead); 4&`d$K
//if(nThreadID == 1) *NIhYg6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e#tWQM3
} 6". v6
P$`k* v
7{=+Va5
Utility.log("Thread " + nThreadID + " is over!"); r`:dUCFE
bDownOver = true; H<`7){iG
//nPos = fileAccessI.write (b,0,nRead); ` B+Pl6l)F
} >9Y0t^Fl
catch(Exception e){e.printStackTrace ();} piPV&ytI
} ]=]`Mnuxb
} S'AS,'EnY
YzAGhAyw
v,c:cKj
//打印回应的头信息 X,+N/nku
public void logResponseHead(HttpURLConnection con) 1swqs7rR|
{ yrrP#F
for(int i=1;;i++) <d3N2
{ l`AA<Rj*O-
String header=con.getHeaderFieldKey(i); v;R+{K87
if(header!=null) ]B-3Lh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "& q])3h=
Utility.log(header+" : "+con.getHeaderField(header)); xgB-m[Xi
else jR,3-JQ
break; +}!FP3KgT
} >zcp(M98
} [~IFg~*,
~^"s.Lsb
!tv+,l&L
public void splitterStop() >U[YSsFt6
{ JztSP?
bStop = true; UL\gcZ Zkl
} $PKUcT0N9
(C8r^m|A
.&c!k1kH
} KH76Vts
~px)Jd
uze5u\
/* $t42?Z=N&z
**FileAccess.java "Bbd[ZI8
*//文件访问(定位，写) 5JRj'G0I
package NetFox; }h_= n>
import java.io.*; ,zH\&D$>u
bjGQ04da
W&Gt^5
public class FileAccessI implements Serializable{ 3r,^is
c9N5c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RiM!LX
RandomAccessFile oSavedFile; N"o+;yR
long nPos; 8&KqrA86
>qjV(_?F-
*Wz\FixP0
public FileAccessI() throws IOException ?;)F_aHp
{ qz/d6-0"
this("",0); wZ =*ejo
} rpO>l
:yC|Q)
xSoXf0zq:
public FileAccessI(String sName,long nPos) throws IOException @jevY81)
{ 04cNi~@m
oSavedFile = new RandomAccessFile(sName,"rw"); #mcU);s
this.nPos = nPos; 0I@Cx{$
oSavedFile.seek(nPos); +zn207.`
} tM;S )S(=
G@;I^_gN
;Q} H'Wg,
public synchronized int write(byte[] b,int nStart,int nLen) f.y~Sew
{ CHRO9
int n = -1; o|0QstSCl
try{ /*yPy?
oSavedFile.write(b,nStart,nLen); 0al8%z9e@
n = nLen; Pb-Ft=
} trC+Etc
catch(IOException e) l]o)KM<
{ ;BMm47<
e.printStackTrace (); &k2nt
} S0<m><|kl
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d~b#dcv$"
return n; kwd)5J
} $"&U%3
@)YQiE$
cWA$O*A
} t846:Z%[
Ut xe
.4NQ2k1io
/* MjHjL~Tg
**SiteInfoBean.java axW4cS ?
*/ Qb;5:U/x
package NetFox; `b{.K,
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G$D6#/rR
public class SiteInfoBean { nBVknyMFNF
!B3lsXLSY
j>0~"A
private String sSiteURL; //Site's URL S-Y(Vn4
private String sFilePath; //Saved File's Path Xkv+"F=-
private String sFileName; //Saved File's Name '0xJp|[xVP
private int nSplitter; //Count of Splited Downloading File RO"*&o'K'
H?=D,
j8G>0f)
public SiteInfoBean() !I? J^0T
{//nSplitter的缺省值为5 D=fB&7%@
//default value of nSplitter is 5 dIo|i,-
this("","","",5); DvuL1MeKo
} M]>JI'8
,QpDz{8
qKL_1 ~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3o'SY@'W
{ h,@x5q>g
sSiteURL= sURL; \4SFD3$&
sFilePath = sPath; IpxFME%!
sFileName = sName; iDO~G($C
this.nSplitter = nSpiltter; _e_]$G/TM
7#,+Q(2
c3lfmTT6^
} Ej1 [ry
>NwrJSx
RU`TzD
public String getSSiteURL() X/1Z9a+W
{ @T1>%oi
return sSiteURL; 'ce9v@(0
} ^;YD3EZw
H[x9 7r
9wKz p
public void setSSiteURL(String value) e7L;{+XI
{ UhCd,
sSiteURL = value; a~ REFy
} B>47Ic
CSU>nIE0
Qb# S)[6s+
public String getSFilePath() @F7QQs3
{ 3iWLo Qm
return sFilePath; 1'_OM h*;
} of& vQ
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kd\yHI9A
public void setSFilePath(String value) Fr%KO)s2
{ "<O?KO3K
sFilePath = value; !9)*.9[8
} N7#GK]n%/}
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5. l&nt'
public String getSFileName() |E7]69=P
{ hV8A<VT
return sFileName; .Yu,&HR
} *`jEg=)
'ZDa*9nkF
9)YG)A~<
public void setSFileName(String value) rWvJ{-%
{ /|DQ_<*
sFileName = value; E_yh9lk
} #-VKk
N]=.I
=C:0='a
public int getNSplitter() Sdt @"6
{ xjX5PQu
return nSplitter; LQQhn{[D
} (?3(=+t
<n`|zQ
-zTeIvcy5
public void setNSplitter(int nCount) p{U8z\
{ 1IsR}uLh
nSplitter = nCount; [,e_2<
} O0I/^
} 2Vi[qS^
l:[=M:#p
P~*fZ)\}F@
/* 7)]G"m{
**Utility.java {oZ]1Qf_
*/ d8K^`k+x
package NetFox; 2-CK:)n/#
qy]-YJZ
]Lh\[@#1f
public class Utility { K4tX4U[Z
&vn9l#\(
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public Utility() 0jyokER
{ <*\J 6:^n
Ea !j-Lbo
])JJ`Z8Bk
} I F@M
*Zvw&y*
//线程睡眠 KXGs'D
public static void sleep(int nSecond) v7R&9kU{
{ D'&LwU,o
try{ nZ*P:K t:
Thread.sleep(nSecond); /IC'R"V a
} F, "x~C
catch(Exception e) wfdFGoy(
{ 8+u8piG
e.printStackTrace (); y{N9.H2
} a !IH-XJ2
} x\%egw
>&VL2xLy
//日志 !2Orklzd1
public static void log(String sMsg) 1 W0;YcT]
{ ~JXHBX
System.err.println(sMsg); >W;i2%T
} )~/U+,
&0g,Xkr
_(hwU>.
public static void log(int sMsg) d}ZHY[
{ ff#-USK^R
System.err.println(sMsg); c&++[
} 4(R2V]
} &Yg/08*
;i9CQ0e?
,:`6x[ +
/* asg>TOW
**TestMethod.java }]I?vyQ#V
*/ 'm|m+K83
package NetFox; ! Cl/=0$[L
R%%`wmG)"
GHy#D]Z
public class TestMethod { c #kV+n<
}kj6hnQ
2An`{')
public TestMethod() 8|({ _Z
{ ///xx/weblogic60b2_win.exe %U GlAyj
try{ >|?T|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eEQ[^i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C~qhwwh
SiteFileFetch fileFetch = new SiteFileFetch(bean); .jp]S4~
fileFetch.start(); 0Mg8{
} ~8*oGG~s
catch(Exception e){e.printStackTrace ();} PoJ$%_a}
<^U(ya
$VWzv4^:
} s3{s.55{m
Yys~p2
~7pjk
public static void main(String[] args) +ZKhmb!
{ au|^V^m
new TestMethod(); X:lPWz!7{
} Z~c'h
} wkD:i2E7
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