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)); $3xDjiBb
} h-fm)1S_
for(int i=0;i<nEndPos.length-1;i++) }\1V%c
{ Nz:p(X!
nEndPos = nStartPos[i+1]; P!gY&>EU
} |@VhR(^O$
nEndPos[nEndPos.length-1] = nFileLength; $."Fz x
} #<G:&
} ,{_56j^d,
SeuDJxqopD
!&5|:96o
//启动子线程 89t"2|9 u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /Mj|Px%
for(int i=0;i<nStartPos.length;i++) 2fXwJG'
{ 8! /ue.T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zzmo7kFx3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7!;zkou
nStartPos,nEndPos,i); V P(JV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7Kpv fyL{
fileSplitterFetch.start(); 2InM(p7j~K
} u+c2 m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z\YLO%Mm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Mm!;+bM%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >8&fFq
nEndPos = " + nFileLength); n8JM 0 U-
// fileSplitterFetch[nPos.length-1].start(); aSI%!Vg.
i=&]%T6Qk
)1 QOA
//等待子线程结束 9A87vs4[
//int count = 0; /S@iF
//是否结束while循环 R G~GVf
boolean breakWhile = false; di7cCn
kOC0d,
-j1]H"-
while(!bStop) *?A!`JpJn
{ 'j!n
write_nPos(); ]W5p\(1g
Utility.sleep(500); A\v53AT
breakWhile = true; dF5y' R'
|io)?`pj
[zSt+K;
for(int i=0;i<nStartPos.length;i++) PEaZ3{-
{ :ciD!Ly
if(!fileSplitterFetch.bDownOver) -Ir>pY\!
{ bDD29
breakWhile = false; E33WT{H&_'
break; uo(LZUjPbN
} 6$l?D^{
} 24wr=5p]Q
if(breakWhile) K[x=knFO
break; KOoV'YSC[(
8idIJm%y
@LSX@V
//count++; u|k_OUTq
//if(count>4) y qK*E*
// siteStop(); cucT|y
} ?}= $zN
jv6>7@<G
1=e(g#Ajn\
System.err.println("文件下载结束！"); lXEnm-_
} ;|W:,a{kS
catch(Exception e){e.printStackTrace ();} b|iIdDK
} &VcO,7 A|
K /%5\h
0g; o6Fg
//获得文件长度 I!Mkss xc
public long getFileSize() 4N= gl(
{ &wN}<Ge6
int nFileLength = -1; r%NzKPW'
try{ Vv+ oq5hf
URL url = new URL(siteInfoBean.getSSiteURL()); 4n1 g@A=y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {,?Gj@$
httpConnection.setRequestProperty("User-Agent","NetFox"); +;=>&XR0m
KHGUR(\Rd6
)*Wz5x
int responseCode=httpConnection.getResponseCode(); LI^D\
if(responseCode>=400) j?g#8L;W\w
{ QL2 `X2
processErrorCode(responseCode); "xn,'`a
return -2; //-2 represent access is error S~&9DQNj
} "-j96 KD
x(p/9$.#
m\E=I5*/
String sHeader; ^:,wk7
ooP{Q r
y=jZ8+M
for(int i=1;;i++) RD;A
{ UMT}2d%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B\l0kiNT
//Utility.log(in.readLine()); q(4Ny<=,'K
sHeader=httpConnection.getHeaderFieldKey(i); .u`A4;;Gw
if(sHeader!=null) {xOzxLB;
{ \Co Z+
if(sHeader.equals("Content-Length")) i6y=3k
{ e@S\7Ks
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q8,,[R_
break; 3#GIZL}!x
} *I}_g4
} qT&zg@m
else oel?we6
break; wDW/?lT&
} <q Q@OUI
} E>O@Bv
catch(IOException e){e.printStackTrace ();} de[NIDA;`
catch(Exception e){e.printStackTrace ();} 0-57_";%Q
;%cW[*Dw
25r3[gX9`
Utility.log(nFileLength); '@IReMl
B__e*d:)!m
.9Dncsnf,`
return nFileLength; 5@ Hg 4.
} 9xE_Awlc85
D9hq$?
TI0=nfj
//保存下载信息（文件指针位置） 4Lz[bI
private void write_nPos() H+@?K6{h
{ ~:|V,1
try{ /b/ 6*&
output = new DataOutputStream(new FileOutputStream(tmpFile)); Og?GYe^_
output.writeInt(nStartPos.length); NRspi_&4J
for(int i=0;i<nStartPos.length;i++) Y{Lxo])e
{ $vn)(zn+
// output.writeLong(nPos); ;ZMIYFXRqh
output.writeLong(fileSplitterFetch.nStartPos); P{Q$(rOe
output.writeLong(fileSplitterFetch.nEndPos); *i!t&s
} 1u(n[<WtT_
output.close(); {Z Ld_VGW
} Hw62'%
catch(IOException e){e.printStackTrace ();} k![H;}W
catch(Exception e){e.printStackTrace ();} 2MW7nIEs
} Z|)1ftcC
{~G~=sC$
LlVbY=EX7
//读取保存的下载信息（文件指针位置） {<#b@=G
private void read_nPos() l-x-
{ |CQ0{1R1
try{ ]86*k%A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H\a\xCP3
int nCount = input.readInt(); +At0V(
nStartPos = new long[nCount]; '+'h^
nEndPos = new long[nCount]; @hrIu" '!
for(int i=0;i<nStartPos.length;i++) 2OqEyXh
{ |$+/IxDP
nStartPos = input.readLong(); @=Dc(5`[
nEndPos = input.readLong(); `DM)tm3&m
} W1ndb:
input.close(); rj?c
} Ug4o2n0sk
catch(IOException e){e.printStackTrace ();} 1Tev&J
catch(Exception e){e.printStackTrace ();} C~.T[Mlu
} &5G@YQD1e
q]*jTb
Md8<IFi9]Q
private void processErrorCode(int nErrorCode) P8;1,?ou
{ A]drNFE
System.err.println("Error Code : " + nErrorCode); WLta{A?
} 0O-"tP8o
( )f)
tCPK_Wws?Z
//停止文件下载 "5?1S-Vl
public void siteStop() rhly.f7N=A
{ 'tU\~3k
bStop = true; (.L?sDQ</z
for(int i=0;i<nStartPos.length;i++) >p" U|
fileSplitterFetch.splitterStop(); p _3xW{I
'/AX'U8Y
)_?h;wh 84
} 17 0r5
} 7#7|+%W0
//负责部分文件的抓取 x"cB8bZ!$
**FileSplitterFetch.java IYH4@v/#
*/ 5g$>J)Ry
package NetFox; 1'8-+?r
mgM"u94-]
oTcf[<
import java.io.*; ;d_<6|*M
import java.net.*; <=w!:
!4 lN[
@O-\s q
public class FileSplitterFetch extends Thread { ]1W]
)r)ZmS5O
8#o2qQ2+
String sURL; //File URL <aI}+
long nStartPos; //File Snippet Start Position Cb.M
long nEndPos; //File Snippet End Position */K]sQZa
int nThreadID; //Thread's ID (v? rZv
boolean bDownOver = false; //Downing is over B7'yc`)H
boolean bStop = false; //Stop identical Q&"oh
FileAccessI fileAccessI = null; //File Access interface BMV\@Sg
|sP0z !)b
6BM$u v4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *X}2
{ ASr@5uFR
this.sURL = sURL; aygK$.wos
this.nStartPos = nStart; W"CG&.
this.nEndPos = nEnd; GdrVH,j
nThreadID = id; S2W@;XvV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UIht`[(z
} r6:e 423
W/~q%\M {
)UVekkq>Q
public void run() i->G{_gH
{ |`{$Ego:
while(nStartPos < nEndPos && !bStop) i XGy*#>V
{ OPogH=vf
>l=^3B,j
IY mkZ?cW
try{ _{eA8J(A<
URL url = new URL(sURL); G-;EB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?du*ITim
httpConnection.setRequestProperty("User-Agent","NetFox"); m&be55M;
String sProperty = "bytes="+nStartPos+"-"; 3"k n5)x
httpConnection.setRequestProperty("RANGE",sProperty); 3SPXJa\i
Utility.log(sProperty); P:3o}CB1I
r}:U'zlC{
5@I/+D
InputStream input = httpConnection.getInputStream(); "}H2dn2n
//logResponseHead(httpConnection); a0Fq$
-%{+\x2
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byte[] b = new byte[1024]; 5P 5Tgk
int nRead; )e6sg]#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *~b~y7C
{ {MDM=;WP_
nStartPos += fileAccessI.write(b,0,nRead); FP*kA_z$
//if(nThreadID == 1) FT-=^VA\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9RkNRB)8
} t)~$p#NS
V{x[^+w7X~
3a=\$x@
Utility.log("Thread " + nThreadID + " is over!"); LX=v _}l J
bDownOver = true; o=xMaA
//nPos = fileAccessI.write (b,0,nRead); 0<fQjXn
} BlcsDB =ka
catch(Exception e){e.printStackTrace ();} ziM@@$.F
} kmtkh"
} Z5EII[=$o
b@K1;A! S
}qZ^S9
//打印回应的头信息 tAujm*|&
public void logResponseHead(HttpURLConnection con) aH8]$e8_,\
{ ;W FiMM\
for(int i=1;;i++) ez5>V7Y
{ yMD0Tj5ZQ
String header=con.getHeaderFieldKey(i); L 7LUy$M-<
if(header!=null) :C,}DyZy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -pQ?ybQ
Utility.log(header+" : "+con.getHeaderField(header)); giW9b_
else =ReSlt
break; 2pP"dX
} Q:b0!
} HNlW.y"
$'<$:;4b3
VRSBf;?
public void splitterStop() *m`x/_y+
{ M 8(w+h{
bStop = true; Dqd2e&a\
} |_ U!i
q]SH'Wd
Z$6B}cz<
} ];N/KHeZ
PpF`0w=1%l
|)*!&\Ch
/* jJ,y+o
**FileAccess.java ,wv>G]v
*//文件访问(定位，写) hPCSAo!|
package NetFox; #MiO4zXgd
import java.io.*; 8+32hg@^F
we@*;k@_
B7oUS}M
public class FileAccessI implements Serializable{ 2=1qmQE
kqq1;Kd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s;]"LD@
RandomAccessFile oSavedFile; gi)C5J4
long nPos; :7(d6gEL
7| j rk
w"O;: `|n
public FileAccessI() throws IOException ;M\Cw.%![
{ 5Kk}sxol
this("",0); L%-ENk
} +"~*L,ken0
0 wDhX
1(%6X*z
public FileAccessI(String sName,long nPos) throws IOException Ub4)x
{ 8H8Q
oSavedFile = new RandomAccessFile(sName,"rw"); \]\h,Y8
this.nPos = nPos; ?`6Mfpvj96
oSavedFile.seek(nPos); &>K|F >7q
} IMpL+W.
Ke~!1S8=
|t;Ktl
public synchronized int write(byte[] b,int nStart,int nLen) T| R!Aw.
{ rL?{+S]&^)
int n = -1; n0%S: (
try{ 3x z z* <
oSavedFile.write(b,nStart,nLen); `1y@c"t
n = nLen; |It{L0=U
} !d[]Qt%mA
catch(IOException e) ,JPDPI/a
{ HW"5MZ8E
e.printStackTrace (); s:z
} _)4zm
BIg2`95F|
x@pzgqi3
return n; =CCddLO
} s5MG#M 9
'RNj5r
&lxMVynL
} LJt5?zQKrW
,">CPl]
}wEt=zOJ
/* 0G+qF96
**SiteInfoBean.java 7ks!0``
*/ /1=x8Sb
package NetFox; n^l5M^.
%%h.`p1
m93{K7O2e
public class SiteInfoBean { )5o6*(Y
uOZSX.o^
XSx'@ qH
private String sSiteURL; //Site's URL 0$U\H>r
private String sFilePath; //Saved File's Path l^$U~OB8k
private String sFileName; //Saved File's Name M.C`nI4
private int nSplitter; //Count of Splited Downloading File zW.Ltz
aghlYcPg
y'JJ#7O=
public SiteInfoBean() zhyf}Ta'
{//nSplitter的缺省值为5 2j1HN
//default value of nSplitter is 5 4e?cW&
this("","","",5); :&E~~EUW
} eQqCRXx
VjZb\ d4
#ZHKq7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6r[pOl:
{ I^D*) z
sSiteURL= sURL; 5D3&6DCH
sFilePath = sPath; M[_Ptqjb
sFileName = sName; 'l-VWqR-
this.nSplitter = nSpiltter; ?4Rq +
LVL#qNIu
(?.h<v1}
} ?b(DDQMf
M,Lq4bz
+hH7|:JQ
public String getSSiteURL() &@PAv5iNf
{ RGY#0.Z}
return sSiteURL; Y$qjQ1jF+
} Ct3+ga$
"#Q"gC.K
ER4#5gd
public void setSSiteURL(String value) 7EL0!:Pp3
{ X'2%'z<
sSiteURL = value; *2YWvGc
} 0zA:?}
'6T *b
5xH*&GpL7
public String getSFilePath() i2LN`5k
{ |(Xxi
return sFilePath; HEK?z|Ne
} Y`xAJ#= ,i
i}))6
_e|-O>#pl
public void setSFilePath(String value) B5;94YIN
{ eYv+tjIF
sFilePath = value; BfW@f
} ksYPF&l
A=*6|1w;
$! g~pV
public String getSFileName() nyG5sWMpe
{ q1/mp){
return sFileName; hm1.UE
} ;*20b@
~AF' 6"A
T7M];@q
public void setSFileName(String value) obgO-d9l
{ Ti#x62X{
sFileName = value; X: Be'
} Maiyd
a]I~.$G
M%Q_;\?]
public int getNSplitter() AJP-7PPD
{ gO]8hLT
return nSplitter; :1#$p
} cZw_^@!
2d&HSW
>R\!Qk
public void setNSplitter(int nCount) 6%&w\<(SG
{ 8%b-.O:_$
nSplitter = nCount; z7Z!wIzJ
} pWb8X}M
} l!}7GWj
(IAR-957pN
YD5mJ[1t"2
/* os+]ct
**Utility.java tA K=W$r
*/ :,'.b|Tl.b
package NetFox; U a1Z,~ *
c{i\F D
q6P5:@
public class Utility { D:N\K/p
NRe=O*O
36 ]?4, .
public Utility() z_Pq5
{ qqu]r
LO)QEUG
zR}vR9Ls
} tz%H1`
z*N%kcw"
//线程睡眠 Z$K[e
public static void sleep(int nSecond) $rQi$w/
{ $oi8<8Y
try{ Ga;Lm?6-
Thread.sleep(nSecond); $ Vsf?ID
} qwd T=H
catch(Exception e) Dh9C9<Ta:
{ s>ZlW:jY
e.printStackTrace (); XeAH.i<
} rX|{nb
} q9(hn_X@/
1_)Y{3L
//日志 0-Wv$o[
public static void log(String sMsg) v&"sTcS|
{ 4/&.N]
System.err.println(sMsg); er>@- F7w
} x\5\KGw16
QV=|' S
<T$rvS
public static void log(int sMsg) en16hd>^W:
{ AD"L>7
System.err.println(sMsg); h{e?Fl
} twql)lbx
} qB3=wFI
d-#yN:}0
&t74T"(d
/* q&: t$tSS
**TestMethod.java !f#[4Xw
*/ b*cVC^{Dy
package NetFox; 6 $+b2&V
B|-W
8?t}S2n2
public class TestMethod { l'"Ici#7Ls
ztV%W6
^FK-e;J
public TestMethod() /6#i$\ j
{ ///xx/weblogic60b2_win.exe 2S-z$Bi}]
try{ h x hl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cvtz&dH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bO+L#Kf
SiteFileFetch fileFetch = new SiteFileFetch(bean); N-Sjd%Z
fileFetch.start(); 2?c%<_jPA
} jp#/]>(9Z
catch(Exception e){e.printStackTrace ();} fZ pUnc
B..> *Xb
zR }vw{
} @}A3ie'w
lFc^y
@)3orH
public static void main(String[] args) ~@'DYZb- H
{ jN sM&s,
new TestMethod(); I<$m%
} Dmn{ppfyb
} ]{pH,vk-
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