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)); E~`l/ W
} 8C8,Q\WV(~
for(int i=0;i<nEndPos.length-1;i++) q}cm"lO$
{ )<[)7`
nEndPos = nStartPos[i+1]; [^0 S#,L
} pYz\GSd
nEndPos[nEndPos.length-1] = nFileLength; N;R I A
} T7?cnK"
} 0[.T`tpN'
^0HgE;4
,$(a,`s)
//启动子线程 2`U+ !
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D+"+m%^>C
for(int i=0;i<nStartPos.length;i++) v4vIcHDs
{ X ;Cl8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;S+]Z!5LT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x&*2R#Ai
nStartPos,nEndPos,i); og`K!d~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rmJ`^6V
fileSplitterFetch.start(); NM+(ss'
} >>%E?'9A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3gs!ojG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #83pitcc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q!AcMd\
nEndPos = " + nFileLength); (D2N_l(`<
// fileSplitterFetch[nPos.length-1].start(); .O6(QI*
%/w%A:y#&
Ni>!b6Z`[
//等待子线程结束 w@x||K=Z
//int count = 0; v,d'SR.
//是否结束while循环 /wU4^8Hz
boolean breakWhile = false; M`p[ Zq
w\y)
<op|yh3Jkk
while(!bStop) w7Ij=!)
{ 11?d,6Jl
write_nPos(); #oJ%i+V
Utility.sleep(500); =[LUOOR*]
breakWhile = true; 8 `}I]
_~bG[lX!
mr>dZ)
for(int i=0;i<nStartPos.length;i++) ffR<G&"n~b
{ z!aU85y
if(!fileSplitterFetch.bDownOver) 0DX)%s,KO
{ @1s 2#)l(
breakWhile = false; Vp1Ff
break; s'/ZtH6>C
} cYz|Ux
} yq12"Rs
if(breakWhile) #Wq@j1?
break; #vzt6x@*
6e%ZNw{#=
=0mn6b9-=
//count++; Axw+zO
//if(count>4) h^'+y1
// siteStop(); _b9>ZF~
} rA /T>ZM
eFC~&L;
a+<{!+3v
System.err.println("文件下载结束！"); ,c|Ai(U
} EbnV"]1
catch(Exception e){e.printStackTrace ();} <=]:ED $V@
} )yUSuK(Vu
95sK;`rE+
3|BB#;
//获得文件长度 +NTC!/
public long getFileSize() M8${&&[;
{ t8.^YTI
int nFileLength = -1; C(n_*8{
try{ cUr5x8<W).
URL url = new URL(siteInfoBean.getSSiteURL()); _ ($U\FW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7{p6&xXx
httpConnection.setRequestProperty("User-Agent","NetFox"); ~p x2kHZ
lBLL45%BIN
lX64IvG8+o
int responseCode=httpConnection.getResponseCode(); `#?]g!
if(responseCode>=400) 'u3,+guz
{ F#a'N c9
processErrorCode(responseCode); w%$J<Z^-?
return -2; //-2 represent access is error %ZX3:2
} Ge1"+:tbJ
~cSE 9ul
)i<Qg.@MX
String sHeader; >[S\NAE>
$:D\yZ,
>,x``-
for(int i=1;;i++) lJt?0;gn
{ WmuYHEU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4VhKV JX
//Utility.log(in.readLine()); QBjvbWoIG(
sHeader=httpConnection.getHeaderFieldKey(i); (Q"~bP{F
if(sHeader!=null) >cH}sNHy
{ 7 lu_E.Bv
if(sHeader.equals("Content-Length")) 4wPP/`
{ 7n7UL0Oc1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?@QcKQ@
break; ~^l;~&
} x#fv<Cj4
} KebC$g@W
else A'n{K#
break; WNSEc%
} J7wIA3.O
} o,'Fz?[T%
catch(IOException e){e.printStackTrace ();} CP Ju=
catch(Exception e){e.printStackTrace ();} Va^(cnwa
yC7lR#N8j0
lT_dzO
Utility.log(nFileLength); .9q`Tf
QObHW[:F
8|tnhA]~
return nFileLength; 3*N0oc^m
} 3x>Y
f1 `E-
JG@Zb}b
//保存下载信息（文件指针位置） xn anca
private void write_nPos() ?N&s.
{ 1ezBnZJg
try{ T3PwM2em_`
output = new DataOutputStream(new FileOutputStream(tmpFile)); d?aZk-|c
output.writeInt(nStartPos.length); ,3W,M=j)
for(int i=0;i<nStartPos.length;i++) ])?[9c
{ |CPyCM$
// output.writeLong(nPos); :A5h<=[
output.writeLong(fileSplitterFetch.nStartPos); .@psW0T%
output.writeLong(fileSplitterFetch.nEndPos); NtkZ\3
} @4$la'XSx
output.close(); LeYI<a@n@$
} :(;ho.zz
catch(IOException e){e.printStackTrace ();} $Y8iT<nP
catch(Exception e){e.printStackTrace ();} 7#C3E$gn?
} ,%U\@*6=
Y^eF(
!e}4>!L,(^
//读取保存的下载信息（文件指针位置） o_&Qb^W
private void read_nPos() |k]fY*z(
{ [<X ~m
try{ s?PB ]Tr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =z\/xzAwX
int nCount = input.readInt(); B^C5?
nStartPos = new long[nCount]; j|LOg
nEndPos = new long[nCount]; 5:%`&B\
for(int i=0;i<nStartPos.length;i++) 4c<\_\\ck
{ )\J~KB4
nStartPos = input.readLong(); T1;>qgp4b
nEndPos = input.readLong(); u56F;y
} 1i;Cw/mr
input.close(); ptlag&Z
} )1f.=QZN^;
catch(IOException e){e.printStackTrace ();} AsR}qqG
catch(Exception e){e.printStackTrace ();} Wz;@Rl|F
} y 7z)lBy\
%`lLX/4~
2yVQqwQm
private void processErrorCode(int nErrorCode) (V0KmNCW`
{ t:n$9WB)
System.err.println("Error Code : " + nErrorCode); ,fvhP $n
} s1p<F,
n>xuef
iB+ _+A
//停止文件下载 @>+`1C
public void siteStop() 5m\)82s
{ 5>h/LE]"
bStop = true; 4GS:kfti
for(int i=0;i<nStartPos.length;i++) I>lblI$7
fileSplitterFetch.splitterStop(); 37*2/N2
X39%O'
,_@) IN
} Uurpho_~
} h{^MdYJ
//负责部分文件的抓取 "g5MltH
**FileSplitterFetch.java NT{'BJ
*/ izLB4pk$
package NetFox; #)4p,H
S~M/!Xb
ps*iE=D
import java.io.*; umt(e:3f5
import java.net.*; -/_hO$|W
le6eorK8
0Z{u;FI
public class FileSplitterFetch extends Thread { DPfN*a-P(
,nJCqX~/G
$g\p)- aU
String sURL; //File URL /sSM<r]5j
long nStartPos; //File Snippet Start Position @eYD@!
long nEndPos; //File Snippet End Position f6m h_l
int nThreadID; //Thread's ID G<Urj+3/Xo
boolean bDownOver = false; //Downing is over 3&R1C>JS ]
boolean bStop = false; //Stop identical fONycXM]
FileAccessI fileAccessI = null; //File Access interface f7Gs1{
57EL&V%j
X$eR RSW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B[5<&
{ Gz2\&rmN
this.sURL = sURL; QV -ZP'e^
this.nStartPos = nStart; m?=J;r"Re
this.nEndPos = nEnd; P`y.3aK
nThreadID = id; (]-RL A>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "ZuA._
} zuF]E+
lU`t~|>r+
,M :j5
public void run() p{&o{+c
{ K14v6d
while(nStartPos < nEndPos && !bStop) xu@xP5GB^
{ WA5.qw
#-l+cu{
rj/nn)vv;
try{ #;h> x
URL url = new URL(sURL); ]2_=(N\Kt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q)5V3Q]@^
httpConnection.setRequestProperty("User-Agent","NetFox"); TXqtE("BDl
String sProperty = "bytes="+nStartPos+"-"; !E^\)=E)P
httpConnection.setRequestProperty("RANGE",sProperty); XE#$|Z
Utility.log(sProperty); ycf)*0k
2B+qS'OT
hLT?aQLx
InputStream input = httpConnection.getInputStream(); H%{k.#O
//logResponseHead(httpConnection); :bkmm,%O
7_J0[C!G
}/jWa|)f
byte[] b = new byte[1024]; gI/(hp3ob
int nRead; 6UU<:KH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0JW =RW
{ u.}H)wt
nStartPos += fileAccessI.write(b,0,nRead); j%gle%_
//if(nThreadID == 1) hb1eEn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !1l~'/r
} I(b]V!mj:
:g{ybTSEe
>b8-v~o{
Utility.log("Thread " + nThreadID + " is over!"); ]$U A5/a
bDownOver = true; <VhD>4f{]
//nPos = fileAccessI.write (b,0,nRead); wWM[Hus
} /$9We8
catch(Exception e){e.printStackTrace ();} (^58$IW71
} zX6Q7Bc
} 4r#4h4`y|
"i&9RA!1
f[?JLp
//打印回应的头信息 @0%[4
public void logResponseHead(HttpURLConnection con) *DQa6,b
{ /)sP<WPQ6
for(int i=1;;i++) F6_en z
{ hRqr
String header=con.getHeaderFieldKey(i); H`jnChD:M'
if(header!=null) ^OK;swDW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'f8'|o)
Utility.log(header+" : "+con.getHeaderField(header)); ;_0frX
else $y%IM`/w
break; I/u>Gt
} ,x?Jrcx~'C
} < Yc)F.:
-8v:eyc
{:=]J4]
public void splitterStop() H;#C NB<e
{ +K,T^<F;
bStop = true; 7tne/Yz
} szD9z{9"y
Az/B/BLB
JW"n#sR4
} w8zr0z
}|wC7*^)
*d31fBCk%
/* Zh_3ydMD1
**FileAccess.java 5ka6=R(r
*//文件访问(定位，写) WT}xCni
package NetFox; un}!&*+
import java.io.*; D'#,%4P,e\
w%(D4ldp
P1|3%#c
public class FileAccessI implements Serializable{ 9<o*aFgCa
FytGg[#]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2 ]n4)vv,
RandomAccessFile oSavedFile; +`!>lo{X
long nPos; j|{ n?
Qx&7Ceu"
>O0<u
public FileAccessI() throws IOException ,[3}t%Da
{ fP 3t0cp
this("",0); PJ,G_+b!
} (-VH=,Md
ux)Wh.5
+W8kMuM!
public FileAccessI(String sName,long nPos) throws IOException Hm+VGH'H?
{ 2'Raj'2S4
oSavedFile = new RandomAccessFile(sName,"rw"); 8t|?b
this.nPos = nPos; !vuun |
oSavedFile.seek(nPos); R_"6E8N
} #}Bv/`t
xmtD0U1
"G Jhx/zt
public synchronized int write(byte[] b,int nStart,int nLen) ! 6R|
{ s+^1\
int n = -1; 4\j1+&W
try{ 1B$8<NCQ=?
oSavedFile.write(b,nStart,nLen); mRN[lj
n = nLen; # wyjb:Ql
} [}4\CWM
catch(IOException e) l-5O5|C
{ rl-#Ez
e.printStackTrace (); cfy9wD
} n^nQrRIp
(%G>TV
_qH]OSo
return n; B_C."{G
} 0^6}s1d_
C#P>3"
bAUYJPRpy
} =w<iYO
,V''?@
u++a0>N
/* #A:^XAU1Z@
**SiteInfoBean.java +~7[T/v+n
*/ [8vqw(2Tm(
package NetFox; `%~f5<
dP"cm0
/=QsZ,~xo
public class SiteInfoBean { Wxgs66
=@nW;PUZ
G0Z$p6z
private String sSiteURL; //Site's URL @Ph'!
private String sFilePath; //Saved File's Path ]qx!51S
private String sFileName; //Saved File's Name ^;$9>yi1
private int nSplitter; //Count of Splited Downloading File "#pN
C;ME"4,(
:Ye~I;"8
public SiteInfoBean() &E@mCQ1
{//nSplitter的缺省值为5 #v4^,$k>
//default value of nSplitter is 5 fT<3~Z>m
this("","","",5); To-$)GQ@W
} #IeG/t(
\*pS4vy5x
p*JP='p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @P[%6 d
{ mS.!lkV
sSiteURL= sURL; Ds@K%f(.?w
sFilePath = sPath; >b~Q%{1
sFileName = sName; !Nbi&^k B
this.nSplitter = nSpiltter; ,t|_Nc
MfA%Xep
V'9OGn2v
} slLTZ]
xscR Bx
~8'HX*B]z
public String getSSiteURL() |1Nz8Vr.
{ mn(MgJKQ\
return sSiteURL; ANR611-a
} [P]M)vJ**
Q[lkhx|.B
c~6ywuq+M`
public void setSSiteURL(String value) I,V'J|=j
{ $>Gf;k
sSiteURL = value; [3qJUJM
} ;cb='s
r%LG>c`^
[p)2!]y
public String getSFilePath() y }h2
{ YL[y3&K
return sFilePath; 2(GLc*B>
} =wa5\p/
e)i-$0L"
K%SfTA1TCB
public void setSFilePath(String value) D:(h^R0;
{ "T}HH
sFilePath = value; M[e{(iQ:
} GF0Utp:Zf;
rNgAzH
ul"Z% 1]
public String getSFileName() QdIoK7J 9
{ zeH=py[n
return sFileName; fJi?~[5<
} .o8pC
sEx\7tK
eqpnh^0}d
public void setSFileName(String value) ^!O2Fw
{ \d w["k
sFileName = value; C+gu'hD
} 1i Q(q\%
|D8c=c%
g$8aB{)
public int getNSplitter() 8)J,jh9q
{ "||G`%aO+t
return nSplitter; Z3iX^
} RP wP4Z
> !HC ?
m h|HEkM
public void setNSplitter(int nCount) ry4:i4/[
{ >*}m.'u
nSplitter = nCount; > 'JWW*Y!
} k59.O~0V
} 6<UI%X
IZ]L.0,
$U%N$_k?
/* oXqx]@7
**Utility.java tNW0 C]
*/ ^X<ytOd5
package NetFox; 3N{ ZX{}
E8We2T[^M
|U="B4
public class Utility { ||4++84{
y(Q.uYz*
3<6P^p=I
public Utility() (' i_Xe
{ 79U7<]-!
;] #Q!
N37#Vs
} 8V:yOq10
0y#TGM|0D
//线程睡眠 x0L,$Ol
public static void sleep(int nSecond) glWa?#1
{ /A`Lyp#
try{ jt",\%j
Thread.sleep(nSecond); N)$yBzN
} $EuI2.o
catch(Exception e) y#e<]5I
{ O[&G6+
e.printStackTrace (); p2Fi(BW*q
} q.RW_t~
} C6,W7M[c
lb#`f,r>
//日志 ,An*w_
public static void log(String sMsg) v>mr
{ %C*h/AW)'
System.err.println(sMsg); 9{{CNy p
} o=doL{#
&v_b7h
{I"d"'h
public static void log(int sMsg) c::Vh
{ HoKN<w
System.err.println(sMsg); +JL"Z4b@R}
} g ??@~\Ov
} p:^;A/D
5nG$6Hw
%g%#=a;]q
/* 9=;ETLL "
**TestMethod.java ,u<aKae
*/ E+E.z?>S
package NetFox; |Ok1E
uY=}w"Db
7~ok*yGw
public class TestMethod { `=~d^wKYJ3
\9dC z;
9#niMv9
public TestMethod() }!RFX)T
{ ///xx/weblogic60b2_win.exe ,LJX
try{ _p=O*$b.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K)t+lJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }))JzrqAe
SiteFileFetch fileFetch = new SiteFileFetch(bean); To19=,:
fileFetch.start(); m/W)IG>
} %y;Cgo[
catch(Exception e){e.printStackTrace ();} F>A&L8
kculHIa\.
|JH1?n
} p)=Fi}#D\
YvjRJ
bi[gyl#
public static void main(String[] args) c>RS~/Y
{ ~*h` ?A0
new TestMethod(); h+h`0(z
} p,+$7f1S
} w">p 8
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