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)); iITMBS`}
} $IS!GS&:
for(int i=0;i<nEndPos.length-1;i++) R>Dr1fc}
{ =>lX brJ
nEndPos = nStartPos[i+1]; VxS3lR=
} o=#ym4hJ%
nEndPos[nEndPos.length-1] = nFileLength; bI3GI:hp
} Tt9cX}&&
} jz HWs
~ES%=if~Y
00'SceL=`
//启动子线程 :/%Y"0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /P-#y@I
for(int i=0;i<nStartPos.length;i++) wfe4b
{ VwRZgL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5!S#}=f=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,;5%&T
nStartPos,nEndPos,i); ,\X! :y~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1=5HQ~|[TO
fileSplitterFetch.start(); 94et ]u%7
} 6$:Q]zR#'H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `R xCs`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (J.Z+s$:2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fVgN8b|&'
nEndPos = " + nFileLength); _yJz:pa
// fileSplitterFetch[nPos.length-1].start(); q]C_idK=
ItvcN
s3m\
//等待子线程结束 V=5S=7 Z:
//int count = 0; MRXw)NAw
//是否结束while循环 J)yg<*/3
boolean breakWhile = false; x7<NaMK\
k!z<=WA
lwgwdB
while(!bStop) aNY-F)XWa
{ rQlQ^W$=?
write_nPos(); )eT>[['fm
Utility.sleep(500); j0X^,ot@m
breakWhile = true; M*qE)dZjS
&4KUXn[F
2A@oa9
for(int i=0;i<nStartPos.length;i++) Lfcy#3!
{ nA_'jl
if(!fileSplitterFetch.bDownOver) )`{m |\b
{ ubfh4
breakWhile = false; _b/zBFa%
break; TfkGkVR
} -`{W~yz
} iX{2U lF7
if(breakWhile) vdvnwzp!l
break; yA"?Hv\o;
Yq51+\d
B+~ /-3
//count++; n.a2%,|v
//if(count>4) r5UVBV8T
// siteStop(); sRZ<c
} &n_f.oUc
axt;}8
M^8zqAA
System.err.println("文件下载结束！"); |>xuH#Q
} "0Z/|&
catch(Exception e){e.printStackTrace ();} / [49iIzC
} ps:`rVQ7
%Rf9KQ
1hCU"|VH:
//获得文件长度 VVAcbAGJ
public long getFileSize() KMkD6g
{ l4+ `x[^
int nFileLength = -1; Rh)XYCM
try{ R31Z(vY
URL url = new URL(siteInfoBean.getSSiteURL()); 5EVypw?]x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W!\%v"
httpConnection.setRequestProperty("User-Agent","NetFox"); \WTKw x
]g;+7
fU ;H
int responseCode=httpConnection.getResponseCode(); <yEApWd;
if(responseCode>=400) U`EOun,
{ W?aP%D"(i
processErrorCode(responseCode); G8__6v~
return -2; //-2 represent access is error |O>e=HC#q8
} -hm/lxyU
-(WRhBpw
MK/8<i<.
String sHeader; X\H P{$fY_
;T0X7MNx
z7:* ,X
for(int i=1;;i++) /0gr?I1wr7
{ vdgK3I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xFThs,w
//Utility.log(in.readLine()); Z:AB(c
sHeader=httpConnection.getHeaderFieldKey(i); \}.bTca
if(sHeader!=null) V[*>}XQER
{ {.e+?V2>_
if(sHeader.equals("Content-Length")) hg0{x/Dgny
{ 2 yANf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .xT{Rz
break; 4[kyzz x
} DBaZcO(U
} ]9w8[T:O
else Cc{{9Ud
break; LVdR,'lS
} fB7Jx6
} 2BF455e
catch(IOException e){e.printStackTrace ();} 3J 5,V
catch(Exception e){e.printStackTrace ();} s1::\&`za
-?1R l:rM
rA?<\*
Utility.log(nFileLength); y5aPs z
u0=&_Q(=
d6[' [dG
return nFileLength; P=<lY},
} w[3a^
6[R6P:v&'G
EHhc2^e
//保存下载信息（文件指针位置） wnQy
private void write_nPos() GLZ*5kw
{ EyU6^
try{ i={4rZOD^
output = new DataOutputStream(new FileOutputStream(tmpFile)); $")Gd@aR
output.writeInt(nStartPos.length); Y7qQ`|
for(int i=0;i<nStartPos.length;i++) "bRjY?D
{ E24}?t^|
// output.writeLong(nPos); (Ly^+Hjg
output.writeLong(fileSplitterFetch.nStartPos); TTa3DbFp%
output.writeLong(fileSplitterFetch.nEndPos); eE .wnn
} ?Q"<AL>Z
output.close(); "m6G;cv
} \zk>cQ
catch(IOException e){e.printStackTrace ();} +eH`mI0f
catch(Exception e){e.printStackTrace ();} gq*W 0S
} z(.,BB[
-!5l4
qj:[NPwaM
//读取保存的下载信息（文件指针位置） K+M\E[1W
private void read_nPos() `DSFaBj,
{ XI$W
try{ Uea2WJpX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); baTd;`Pn
int nCount = input.readInt(); 1~E4]Ef:W
nStartPos = new long[nCount]; UfO='&U^
nEndPos = new long[nCount]; V,c^Vqy
for(int i=0;i<nStartPos.length;i++) _D{FQRU<YD
{ EFI!b60mc
nStartPos = input.readLong(); 1/ j>|
nEndPos = input.readLong(); %q;y74
} 6?.S-.Mr
input.close(); />:$"+gKo
} B+R|fQ
catch(IOException e){e.printStackTrace ();} C{t}q*fG 5
catch(Exception e){e.printStackTrace ();} q2`mu4B
} rbv
@~7au9.V=X
@QnKaZ8jW
private void processErrorCode(int nErrorCode) *&#M`,#
{ >Q"3dw
System.err.println("Error Code : " + nErrorCode); ?kV_!2U)'K
} K+L9cv4 |*
[z7]@v6b
-R];tpddR5
//停止文件下载 fn7?g
public void siteStop() OaoHN& "
{ #^|2PFh5
bStop = true; YB)I%5d;{
for(int i=0;i<nStartPos.length;i++) kDQE*o
fileSplitterFetch.splitterStop(); 9|@5eN:N
##mBOdx
5=9Eb
} h5aPRPUg
} `)w=@9B)"
//负责部分文件的抓取 Abmi=]\bx
**FileSplitterFetch.java 9]G~i`QQ
*/ :]8A;`G}
package NetFox; } 21!b :a
vs$.i
#-"C_~-MH
import java.io.*; &h6 `hP_
import java.net.*; !VudZ]Sg
+>u 8r&Jw.
5OFB[
public class FileSplitterFetch extends Thread { KNP^k$=)3c
$kR%G{j 4
md\Vw?PkU
String sURL; //File URL O_ $zK
long nStartPos; //File Snippet Start Position r`+G9sj3U
long nEndPos; //File Snippet End Position ]D2d=\
int nThreadID; //Thread's ID 4QiV@#o:
boolean bDownOver = false; //Downing is over 1[a#blL6W
boolean bStop = false; //Stop identical w; f LnEz_
FileAccessI fileAccessI = null; //File Access interface *'{9(Oj
zY4y]k8D*
PCc{0Rp\vk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L0%W;m
{ 4VsttT
this.sURL = sURL; sVnpO$
this.nStartPos = nStart; tgeXX1Eq!
this.nEndPos = nEnd; ?4W6TSW-'
nThreadID = id; t|UM2h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'auYmX
} AuBBSk8($
NVf_#p"h
SU~ljAF4
public void run() bNvc@oo
{ f{(D+7e}
while(nStartPos < nEndPos && !bStop) ~qA\u5sB9@
{ zx?|5=+!
IFF1wfC
9!Fg1h=
try{ H$zDk
URL url = new URL(sURL); !(j<Y0xo:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %wJ?+D/
httpConnection.setRequestProperty("User-Agent","NetFox"); QbWeQ[V{
String sProperty = "bytes="+nStartPos+"-"; G{a_\'7
httpConnection.setRequestProperty("RANGE",sProperty); VZk;{
Utility.log(sProperty); |B\76Nk
`@<)#9'A
uxW<Eh4H*
InputStream input = httpConnection.getInputStream(); I]91{dq
//logResponseHead(httpConnection); j#H&~f
Qb86*
%w3tzE1Hq
byte[] b = new byte[1024]; 0v3 8LBH)
int nRead; 5~i}!n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mw\Pv|
{ ~>3#c#[
nStartPos += fileAccessI.write(b,0,nRead); \LM{.gzT
//if(nThreadID == 1) k& ]I;Aq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7VfPS5se
} d}^hZ8k|
Dv=pX.Z+
<M,=(p{
Utility.log("Thread " + nThreadID + " is over!"); ]L\]Ll;
bDownOver = true; z{U^j:A
//nPos = fileAccessI.write (b,0,nRead); X;dUlSi
} v 5&8C
catch(Exception e){e.printStackTrace ();} t"&qaG{
} <EuS6Pg
} t8~isuiK
p$XvVzW#<
B(R$5Xp
//打印回应的头信息 Y0o{@)Y:
public void logResponseHead(HttpURLConnection con) |Tk'H&
{ :-T[)Q+-3
for(int i=1;;i++) !z+'mF?V+X
{ .fNLhyd
String header=con.getHeaderFieldKey(i); ~<3J9\z1
if(header!=null) BIjkW.uf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D[K!xq
Utility.log(header+" : "+con.getHeaderField(header)); vyruUYFWe
else #nS crs@
break; 'RIx}vPf
} (ZD~Q_O-
} SA,+oq(
E qt\It9
7$JE+gL/7
public void splitterStop() 6LzN#g
{ ?; tz
bStop = true; r]bG,?|
} '.t{\
Pt7yYl&n7^
I=4G+h5p
} qfgw^2aUa
<e$%m(]
3 E!F8GZ
/* i [2bz+Z?
**FileAccess.java ?H21Ru>:*
*//文件访问(定位，写) b'(Hwc\ t
package NetFox; /wJocx]vQ
import java.io.*; rTA#4.*&
8}|!p>
a}kPc}n\
public class FileAccessI implements Serializable{ d@+u&xrd
RWXN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lxtt+R
RandomAccessFile oSavedFile; ?q}:ojrs1
long nPos; '17V7A/t
~{{@m]P
vk|xYDD
public FileAccessI() throws IOException ME'LZ"VT
{ 94u~:'t>V
this("",0); FLaj|Z~#)
} JYa3xeC;
8>!-|VSn
p)*x7~3e
public FileAccessI(String sName,long nPos) throws IOException | =tGrHL
{ FtybF
oSavedFile = new RandomAccessFile(sName,"rw"); }n?D#Pk,
this.nPos = nPos; (Iv*sd *
oSavedFile.seek(nPos); 9]^NAlno
} iq3TP5%i
dp*E#XCr1
ZEG~ek=jM
public synchronized int write(byte[] b,int nStart,int nLen) Vu Ey`c
{ w9CX5Fg
int n = -1; *:Y9&s^6j
try{ snyA
oSavedFile.write(b,nStart,nLen); 9Q&]5|x
n = nLen; gmtS3,
} C@9K`N[*
catch(IOException e) t7,**$ST
{ :<,tGYg/!
e.printStackTrace (); OZ2faf
} z]1g;j
>9X+\eg-
LN=#&7=$c
return n; ez[$;>
} ])vqXjN6"
qex::Qf
M#xol/)h
} @Qd5a(5WM
FES0lw{G#
~?KbpB|
/* X^d}eWP`I
**SiteInfoBean.java s,7OoLE
*/ be>KG ZU0
package NetFox; ?)e6:T(
L^L.;1
\;!g@?CA
public class SiteInfoBean { UX)QdT45Mh
%TzdpQp"
G:Nwi=vN
private String sSiteURL; //Site's URL 9zaSA,}
private String sFilePath; //Saved File's Path eyG[1EEU
private String sFileName; //Saved File's Name 10m`LG
private int nSplitter; //Count of Splited Downloading File 3+V.9TL'a
^aY,Wq
^fti<Lw5
public SiteInfoBean() slV]CXW)t
{//nSplitter的缺省值为5 ^1X 6DH`
//default value of nSplitter is 5 (^^}Ke{J
this("","","",5); ccgV-'IG9
} T,v5cc:nO
^PowL:
j15t8du&O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /mnV$+BE
{ 9+:<RFJ
sSiteURL= sURL; Zu/1:8x
sFilePath = sPath; ]!cLFXa
sFileName = sName; .a}!!\@
this.nSplitter = nSpiltter; je=XZ's,i~
Q6fPqEX=
1yjP`N
} d&%}u1 .
PAv<J<d
l1]'3]P(
public String getSSiteURL() '#CYw=S+
{ Z8WBOf*~e
return sSiteURL; qj,^"rp1:
} DcEGIaW
64f6D"."
kj'
public void setSSiteURL(String value) =p#:v
{ Q=#!wWVP
sSiteURL = value; zA@w[.
} M.KXDD#O
$ZnVs@:S
&F|Wk,y
public String getSFilePath() YG>6;g)Zm
{ \$2zF8
return sFilePath; #\MkbZc d
} E# *`u
{)& b6}2h
QykHB k
public void setSFilePath(String value) 4 zipgw
{ 5z"[{#/
sFilePath = value; 'z">4{5
} fG|+!
k:CSH{s5{
;;n=(cM|z
public String getSFileName() (.~'\@
{ "Kf4v|6;
return sFileName; ,pVq/1
} :w:ql/?X
~)]n67Or~
:*)b<:4
public void setSFileName(String value) EtA,ow
{ \`WAG>'l5
sFileName = value; 7kQ,D,c'
} fh@/fd
kud2O>>
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public int getNSplitter() t2&}
{ ]`eJSk.
return nSplitter; X*rB`M7,
} "gq_^&
LQ4F/[1}
{aWfD XB1
public void setNSplitter(int nCount) B-aJn8>/
{ Aq{7WA
nSplitter = nCount; LrnE6U9
} <^B!.zQ
} 'pl){aL`@u
K@;ls
f{f|frs
/* }7/Ob)O
**Utility.java KPs @v@5M
*/ 1A/li%
package NetFox; =!PUKa3f<
?iNihE
s&Qil07Vl
public class Utility { `jH0FJQ
({p@Ay
"AMsBvzgo
public Utility() =/F\_/Xw
{ D_Cd^;b
T|lyjX$Q]9
K6z-brvw"
} *saO~.-;4
S]&7
//线程睡眠 ^tFgkzXm
public static void sleep(int nSecond) #ui7YUR=2
{ 3Ho<4_I,
try{ 'C|yUsBC
Thread.sleep(nSecond); z3p#`
} oi}\;TG
catch(Exception e) OL)M`eVQ'
{ 3ZU<u;
e.printStackTrace (); ;l'kPUv([
} s7TV@Y)
} 9:jZ3U
7U{g'<
//日志 80qe5WC.2u
public static void log(String sMsg) ;R.l?Bg
{ 3RTraF
System.err.println(sMsg); nFfwVqV
} gAgP("
d ;W(Vm6
,zY!EHpx
public static void log(int sMsg) kKg%[zXS
{ ^atBf![
System.err.println(sMsg); )q+9_KUq
} x9!vtrM\Zr
} /K]<7
4?{e?5)
L E>A|M$X
/* +e%U6&l{
**TestMethod.java L'Fy\K\
*/ *m[ow s
package NetFox; enGjom
o-jF?9m
;eRYgC
public class TestMethod { e-#!3j!'
Zu/}TS9bi
@n##.th
public TestMethod() ~y(-j[
{ ///xx/weblogic60b2_win.exe ,,>b=r_r&
try{ )} H46
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P]G`Y>#$r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0-W{(xy@4
SiteFileFetch fileFetch = new SiteFileFetch(bean); +L86w7
fileFetch.start(); S:En9E
} Bld$<uU
catch(Exception e){e.printStackTrace ();} uII:Y{G
oZV=vg5Dq
a!>yX ex
} 2I#4jy/g
u9*}@{,
H0YxPk)
public static void main(String[] args) XKU+'Tz
{ < g<Lf[n$
new TestMethod(); siHS@S
} ,HxsU,xiG
} 7lvUIc?krW
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