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)); >wmHCOL:
} C 4C/
for(int i=0;i<nEndPos.length-1;i++) "q M
{ i56Rdb
nEndPos = nStartPos[i+1]; FsWp>}o
} ph6'(,
nEndPos[nEndPos.length-1] = nFileLength; G6a 2]
} /96lvn]8lO
} c( U,FUS
!"qT2<A
[niFJIsc
//启动子线程 _3 oo%?}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VED~v#.c
for(int i=0;i<nStartPos.length;i++) T\.(e*hC
{ QCZ88\jX[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GLecBF+>F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a'jUM+D;
nStartPos,nEndPos,i); TY %zw6 #p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P}5bSQ( a3
fileSplitterFetch.start(); iv+a5
} g_c@Kyf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sYDav)L.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c:0n/DC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !;*flr`/
nEndPos = " + nFileLength); b_F1?:#
// fileSplitterFetch[nPos.length-1].start(); ,:L^vG@*
v5a\}S<(
Ly8=SIZ
//等待子线程结束 z/4<x?}+hE
//int count = 0; Uvm.|p_V
//是否结束while循环 3 5.&!4}
boolean breakWhile = false; G-9i
$%DoLpE>
N~=PecQ
while(!bStop) 0*5Jq#5
{ -F`GZ
write_nPos(); 2yn"K|
Utility.sleep(500); |\uj(|
breakWhile = true; <dP\vLH_
i;C` .+
)4B`U(%M~
for(int i=0;i<nStartPos.length;i++) zX*5yNd
{ OXQA(%MK
if(!fileSplitterFetch.bDownOver) }B7Txo,Z
{ |}z5ST%
breakWhile = false; h'&<A_C-7
break; ~%=%5}
} "y"oV[`
} &Hp*A^M
if(breakWhile) 8e>B>'nH
break; jXf@JxQ
5?`4qSUz
V? tH/P
//count++; LJ@(jO{z
//if(count>4) ,hI$nF0}p
// siteStop(); vFdI?(c-
} V':A!
@br)m](@
vb>F)po1}
System.err.println("文件下载结束！"); , p}:?uR
} W+Mw:,>*s
catch(Exception e){e.printStackTrace ();} CUH u=
} `K+%/|!
KZ[TW,Gw
|s/N?/qi
//获得文件长度 Nkj$6(N=zJ
public long getFileSize() *Oy* \cX2[
{ yOEy3d=*
int nFileLength = -1; A+Isk{d
try{ C=o-3w
URL url = new URL(siteInfoBean.getSSiteURL()); Pd&KAu|<`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )-5eIy
httpConnection.setRequestProperty("User-Agent","NetFox"); )-[$m%
WZ6{9/%:
JW0\y+o~
int responseCode=httpConnection.getResponseCode(); q7KHx b
if(responseCode>=400) c]x-mj =
{ L:Rg3eo
processErrorCode(responseCode); kJuG haO
return -2; //-2 represent access is error dpq(=s`s
} wg)Bx#>\L:
B/a`5&G]
Xykoq"dbb
String sHeader; ej_u):G*
#KoI8U"
|g}r
for(int i=1;;i++) AFL'Ox]0
{ ]>[TF'pIAx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0'F/z%SMj
//Utility.log(in.readLine()); vS~tr sI
sHeader=httpConnection.getHeaderFieldKey(i); LWqKSNE;
if(sHeader!=null) FNraof @Oy
{ YFu,<8"swe
if(sHeader.equals("Content-Length")) bi}aVtG~z
{ BV@q@C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W*S4gPGM
break; 7P3/Ky@6
} .yfp-n4H
} b(|&e
else :F"IOPfU5[
break; <& PU%^Ha
} =\2gnk~
} am? k
catch(IOException e){e.printStackTrace ();} tM\BO0
catch(Exception e){e.printStackTrace ();} &@@PJ!&
w?u3e+
jG&HPVr
Utility.log(nFileLength); \Db`RvEmR
3S_H&>K
;\A_-a_(#
return nFileLength; +|g*<0T5<
} rQT%~oM:
LYYz=oZOE!
>CrrxiG
//保存下载信息（文件指针位置） +2:HgW
private void write_nPos() /"`hz6rIv
{ 7{M&9| aK
try{ q M_c-^F
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jf=V<
output.writeInt(nStartPos.length); #]1jvB
for(int i=0;i<nStartPos.length;i++) |)>+& xk
{ u=L Dfn
// output.writeLong(nPos); Kh=\YN\E<
output.writeLong(fileSplitterFetch.nStartPos); y-H9fWi8Y&
output.writeLong(fileSplitterFetch.nEndPos); EZiLXQd_
} P-T@'}lW
output.close(); \(Nx)F
} j<!dpt
catch(IOException e){e.printStackTrace ();} aTm R~k
catch(Exception e){e.printStackTrace ();} ML|?H1m>
} tQNc+>7k+u
$2*_7_Qb
b4^O=
//读取保存的下载信息（文件指针位置） |;|r[aU
private void read_nPos() QhRz57'
{ gzhIOeY
try{ cZYvP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S)ipkuj X
int nCount = input.readInt(); CzreX3i
nStartPos = new long[nCount]; i75\<X
nEndPos = new long[nCount]; e%ro7~
for(int i=0;i<nStartPos.length;i++) p8j4Tc5tQ>
{ I__b$
nStartPos = input.readLong(); TT(R<hL
nEndPos = input.readLong(); PJm@fK(j
} 40 u tmC
input.close(); _(m455HZ
} a3MI+
catch(IOException e){e.printStackTrace ();} *iru>F8r:
catch(Exception e){e.printStackTrace ();} 2Jiy`(P
} r<(UN@T}
H1?C:R
#'f5owk>,
private void processErrorCode(int nErrorCode) ddl]! ^IK
{ $A5O>
System.err.println("Error Code : " + nErrorCode); Kp7)my
} X4\T=Q?uLx
+<@1)qZ(E
]vR Ol.
//停止文件下载 `2+TN
public void siteStop() 32 j){[PL3
{ 0 5?`W&:9
bStop = true; F> Ika=z,
for(int i=0;i<nStartPos.length;i++) 8VU(+%X
fileSplitterFetch.splitterStop(); WQCnkP
JDa_;bqL
POl-S<QV
} E[ -yfP~[
} s=:LS
//负责部分文件的抓取 OB=bRLd.IR
**FileSplitterFetch.java pheu48/f
*/ @mu{*. &
package NetFox; z"z$.c
=ePwGm1:c
5FB3w48
import java.io.*; yMkR)HY
import java.net.*; -@w}}BR
X xwcvE
cCZ$TH
public class FileSplitterFetch extends Thread { gIRZkT`
hEo$Jz`
]==7P;_-
String sURL; //File URL p;, V
long nStartPos; //File Snippet Start Position )AieO-4*
long nEndPos; //File Snippet End Position $aT '~|?
int nThreadID; //Thread's ID & \5Ur^t
boolean bDownOver = false; //Downing is over u&={hJ&7
boolean bStop = false; //Stop identical >_]Ov:5
FileAccessI fileAccessI = null; //File Access interface PmsZ=FY
1xkk5\3]
9+ve0P7$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KU/QEeqbrp
{ P^Og(F8;
this.sURL = sURL; %sZ3Gpi
this.nStartPos = nStart; 8N j}
this.nEndPos = nEnd; _(=g[=Mer
nThreadID = id; )iIsnM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t vW0 W
} $u,A/7\s
B&KIM{j\
BUi,+NdIk
public void run() rKOa9M
{ TL"+Iv2]/$
while(nStartPos < nEndPos && !bStop) #NMQN*J>D
{ @pJ;L1sn
X}={:T+6s
%(%EEt
try{ ]{|l4e4P
URL url = new URL(sURL); w0=/V[fs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M`=\ijUwN
httpConnection.setRequestProperty("User-Agent","NetFox"); Fm&f
String sProperty = "bytes="+nStartPos+"-"; '>bn94$
httpConnection.setRequestProperty("RANGE",sProperty); =*-ac
Utility.log(sProperty); GM^H )8U
r da: ~
.;bU["fn)
InputStream input = httpConnection.getInputStream(); ,Bx0
//logResponseHead(httpConnection); pXQ$n:e
(yEU9R$I"
71<4q{n
byte[] b = new byte[1024]; l%i*.b(
int nRead; -c0*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xjxX4_
{ KF#qz2S
nStartPos += fileAccessI.write(b,0,nRead); MdkL_YP}.
//if(nThreadID == 1) \q!TI x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 06pY10<>X
} nC$c.K'
=(c.8d
D&N3LH
Utility.log("Thread " + nThreadID + " is over!"); vgNrHq&2q
bDownOver = true; 0iMfyW:
//nPos = fileAccessI.write (b,0,nRead); C^]UK
} PK{FQ3b2{
catch(Exception e){e.printStackTrace ();} )P+<=8@a
} #MMp0
} R5},E
O#8lJ%?
X,8Zn06M
//打印回应的头信息 _-v$fDrz
public void logResponseHead(HttpURLConnection con) SBi4i;qD
{ :< ]sJfN
for(int i=1;;i++) u1z!OofN>
{ i3(5 '
String header=con.getHeaderFieldKey(i); Z]Z&PbP
if(header!=null) `i~J0#P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fgo3Gy*#
Utility.log(header+" : "+con.getHeaderField(header)); CRzLyiRvU&
else 7D8 pb0`;J
break; VqOTrB1w/
} =zp{ ^mC
} oq>jCOVh
jW| ,5,43
?^8.Sa{
public void splitterStop() 0+_;6
{ {FC<vx{42
bStop = true; I.2>d_^<
} 8y?q)y9h
S@,x^/vT
-s91/|n
} Ym-mfWo^#
!;k ^
[[4!b E
/* 3)^2X
**FileAccess.java zJ8jJFL+Y
*//文件访问(定位，写) 8l?@ o
package NetFox; PIsXX#`7;
import java.io.*; 4!M0)Nix
Kt"4<'
--`W1!jI@
public class FileAccessI implements Serializable{ Sn;q:e3i{A
nu16L$]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P^BSl7cT
RandomAccessFile oSavedFile; z5f3T D6,
long nPos; ; ?,'jI*1
rO,n~|YJ
]7|qhAh<L
public FileAccessI() throws IOException d5W=?
{ b%j4W)Z
this("",0); uy=<n5`oNG
} #D+.z)iZn
?/Aql_?3
4`"Q!T_'
public FileAccessI(String sName,long nPos) throws IOException :|ytw=3>
{ l2LO,j}
oSavedFile = new RandomAccessFile(sName,"rw"); 1Zp^X:(
this.nPos = nPos; `|[UF^9
oSavedFile.seek(nPos); HN&]`cr;
} o107.s
o|VM{5
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public synchronized int write(byte[] b,int nStart,int nLen) g*%o%Lv
{ QP6a,^];
int n = -1; #t">tL
try{ )Z`OkkabnD
oSavedFile.write(b,nStart,nLen); Aacj?
n = nLen; lI[O!VuKc
} ,z$U=uo
catch(IOException e) z&|sks7
{ H)+wkR!~
e.printStackTrace (); [lj^lN8
} \#'m([<e
hl+ T
1~*JenV-
return n; %bTXu1
} *&F~<HC2+
73E[O5?b
t(- 5l
} ~0{F,R.$
vqwSOh|P9
#X<s_.7DJ
/* )-LSn
**SiteInfoBean.java ZV:0:k.x
*/ 9q<?xO
package NetFox; pH.&OW%
I}/-zyx>=
Z&y9m@
public class SiteInfoBean { /}-LaiS
&?SU3@3|
O#b%&s"o
private String sSiteURL; //Site's URL [PU0!W;
private String sFilePath; //Saved File's Path !~f!O"n)3r
private String sFileName; //Saved File's Name #_fL[j&
private int nSplitter; //Count of Splited Downloading File ,09d"7`X
=Wl}Pgo!
fh}j)*K8
public SiteInfoBean() |uln<nM9
{//nSplitter的缺省值为5 izP>w*/nO
//default value of nSplitter is 5 qH*Fv:qnM
this("","","",5); ^:m7Qd?Z[
} \;Q:a /ur9
G~\=:d=^,`
(fnp\j3w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0$q)uip
{ Yg3emn|a
sSiteURL= sURL; ;rh@q4#
sFilePath = sPath; Vg? 1&8>
sFileName = sName; 8Jf4";
this.nSplitter = nSpiltter; -$kAWP8P4
_WHGd&u
j}@n`[V1
} ns !Mqcm
4VfZw\^
*Q2}Qbu
public String getSSiteURL() Ceak8#|4
{ |jyoT%SQ
return sSiteURL; =(>pv,
} p3{ 3[fDx
Q.L.B7'e7
z] teQaUZ
public void setSSiteURL(String value) R9lb<`
{ Z\*jt B:
sSiteURL = value; co%-d
} $<s 3;>t
%C(^v)"
si3@R?WR6*
public String getSFilePath() =G%L:m*
{ XVkCYh4,
return sFilePath; Kh2!c+Mw
} );5H<[
RL3G7;X
la[>C:8IG
public void setSFilePath(String value) dn@_\5
{ "~/O>.p
sFilePath = value; $23dcC*hI
} $|bdeQPr\
&>%9JXU
R3%&\<a)9
public String getSFileName() 5\eM3w'd
{ ; )J\k2
return sFileName; nf9NJ_8}4H
} 16R0#Q/{+*
V'&`JZK6
ww$Ec
public void setSFileName(String value) ^5BQ=
{ \J,pV
sFileName = value; O4A{GO^q
} &S+ooj
Ow4H7sl
X[KHI1@w
public int getNSplitter() o+^5W
{ %6@->c{
return nSplitter; JP*VR=0k?
} r5S5;jL%t
Z1ZjQt#~+
/32x|Ow# 1
public void setNSplitter(int nCount) Z. G<'
{ wxSJ
nSplitter = nCount; E+e:UBeUV
} Doc_rQYku
} e.jbFSnA
V+&C_PyC
~V6wcXd
/* n(tx'&U"R
**Utility.java L:E?tR}H
*/ eT6T@C](
package NetFox; _/`H<@B_U
q,v)X
9S]]KEGn4
public class Utility { Cmj+>$')0
"8sB,$
7S]<?>*
public Utility() 1'"TO5
{ _[t:Vme}v
5isqBu
?,0 a#lG
} *$yU|,
's_[#a;Vp
//线程睡眠 qaZQ1<e
public static void sleep(int nSecond) p]erk
{ ] g]^^
try{ {f:%+h
Thread.sleep(nSecond); WYXh1_nyk
} '|rhm
catch(Exception e) /U5!]7&gB
{ RJk42;]
e.printStackTrace (); nBJ'ak
} Uon^z?0A
} hWD%_"yhd
-b$m<\0*
//日志 4(D/~OG-6
public static void log(String sMsg) rK} =<R
{ 3P2x%Gp
System.err.println(sMsg); C 5 xsh
} d !=AS
?3=y]Vb+
{q1u[T&r
public static void log(int sMsg) ^R7|x+
{ ^9fY%98
System.err.println(sMsg); %v)O!HC}
} h1REL^!c
} >PmnR>x-rj
S";c7s
&f($= 68
/* PJ3M,2H1b.
**TestMethod.java Ssg1p#0J
*/ bAS/cuZs
package NetFox; Jy?; <
?8]g&V
<e'/z3TbRW
public class TestMethod { L-eO_tTh0
<@H`5[R
{u)>W@Lr
public TestMethod() SS*3Qx:[
{ ///xx/weblogic60b2_win.exe Ci(c`1av
try{ ( we)0AxF'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;fe~PPT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JpE7"Z"~MS
SiteFileFetch fileFetch = new SiteFileFetch(bean); hAU@}"=G
fileFetch.start(); 34<k)0sO
} E)F#Z=)
catch(Exception e){e.printStackTrace ();} \zLKSJ]
[PX%p;"D
nAaY5s0D
} xVN(It7g
fR>"d<;T
jG["#5<?
public static void main(String[] args) H[2W(q6
{ %Hu?syo
new TestMethod(); AjD?_DPc
} IN7Cpg~9%
} P"f4`q
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