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)); pP/@
} ')#,X^
for(int i=0;i<nEndPos.length-1;i++) TZB+lj1
{ x8[MP?Wz
nEndPos = nStartPos[i+1]; =dH$2W)G
} HFtf
nEndPos[nEndPos.length-1] = nFileLength; UTk r.T+2X
} lrEj/"M
} 6m`{Z`c$
%w"nDu2Gcv
ae`|ic
//启动子线程 UQ8bN I7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Omyt2`q
for(int i=0;i<nStartPos.length;i++) IF_DZ
{ \7 a4uc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J)x3\[}Ye
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r6.N4eW.L
nStartPos,nEndPos,i); 3fkk [U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^PqF<d6
fileSplitterFetch.start(); %5B%KCCN
} {]/8skov5]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wD9a#AgEd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KS<Jv;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xAdq+$><
nEndPos = " + nFileLength); d>i13dAI
// fileSplitterFetch[nPos.length-1].start(); Z`_.x &Y
{BV4h%P]:
q~Jq/E"f
//等待子线程结束 Dz&+PES_k
//int count = 0; jPJAWXB4a
//是否结束while循环 Fwfo2
boolean breakWhile = false; *y7 $xa4
Y94MI1O5$
H5xzD9K;/C
while(!bStop) x0+glQrNN
{ Oh!(@
write_nPos(); #@//7Bf%
Utility.sleep(500); ClUSrSp
breakWhile = true; )|]dmQ-
&7[[h+Lb
=nRuY'
for(int i=0;i<nStartPos.length;i++) }C#3O{5
{ oyeG$mpg
if(!fileSplitterFetch.bDownOver) YD_]!HK}
{ AFm1t2,+;
breakWhile = false; Y 62r
break; 8A2z 5Aa
} ;#QhQx
} W|R-J
if(breakWhile) uofLhy!
break; f(Hu {c5yV
+=fKT,-*G!
h4`9Cfrq,
//count++; tYe:z:7l?<
//if(count>4) !]b@RUU
// siteStop(); L* |1/
} $@uU@fLB
+;gsRhWk
HnZPw&*
System.err.println("文件下载结束！"); Ijo(^v@
} ?[= U%sPu=
catch(Exception e){e.printStackTrace ();} 6?gi_3g
} uP|FJLY
SkP[|g'56
j%tEZ"H
//获得文件长度 JF9Hfs/jS
public long getFileSize() []p"3i
{ a6nlt?1?D
int nFileLength = -1; 5Pke8K
try{ 32>x^>G=>
URL url = new URL(siteInfoBean.getSSiteURL()); _l&ucA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `wO}Hz
httpConnection.setRequestProperty("User-Agent","NetFox"); ]PX}b
2*OxA%QELM
>&K!VQ{g
int responseCode=httpConnection.getResponseCode(); 5h^[^*A?
if(responseCode>=400) ]Yz'8uts
{ !#WqA9<
processErrorCode(responseCode); +zO]N&
return -2; //-2 represent access is error .Ff_s
} 1f//wk|
8wFn}lw&
P6Xp<^%E
String sHeader; w|Qd`
!nw[
q=0 pQ1>
for(int i=1;;i++) pXW`+<g0
{ 8(lCi$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p\D >z("
//Utility.log(in.readLine()); Fd8hGj1
sHeader=httpConnection.getHeaderFieldKey(i); d*-Xuv
if(sHeader!=null) =AkX4k
{ 3,$iGe
if(sHeader.equals("Content-Length")) WU\m^!`w=F
{ F`&>NQb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2d&^Sp&11
break; kL;t8{n
} W"qL-KW
} O E|+R4M
else KH}t:m+h
break; uPDaq ]A
} 3$_2weZxYn
} UR:n5V4
catch(IOException e){e.printStackTrace ();} A{`]&K1u
catch(Exception e){e.printStackTrace ();} 6>B \|
fPz=KoN
>\bPZf)tJ)
Utility.log(nFileLength); /'&v4C^y>
`d`&R.'
!-(J-45
return nFileLength; {B^pnLc
} 4ftj>O
zoXuFg
l1RlYl5
//保存下载信息（文件指针位置） `|,tCM&-
private void write_nPos() AM/lbMr
{ l<N?'&
try{ -$R5
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^[TOZXL`:
output.writeInt(nStartPos.length); vKkf2 7
for(int i=0;i<nStartPos.length;i++) RKk"
{ &kx\W)
// output.writeLong(nPos); N|N/)
output.writeLong(fileSplitterFetch.nStartPos); .v l="<
output.writeLong(fileSplitterFetch.nEndPos); p JX, n
} v=MzI#0L
output.close(); \e0x,2
} _IKQ36=
catch(IOException e){e.printStackTrace ();} ca}S{"
catch(Exception e){e.printStackTrace ();} llqDT-cp
} M6x;BjrV
G5+]DogS
Eq7gcDQ
//读取保存的下载信息（文件指针位置） G>j"cj
private void read_nPos() y`+<X{V5L
{ n|Ma&qs
try{ gTD%4V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); STRyW Ml
int nCount = input.readInt(); ZjavD^ky
nStartPos = new long[nCount]; HnK/A0jM
nEndPos = new long[nCount]; dw99FA6
for(int i=0;i<nStartPos.length;i++) 4ioNA/E
{ u2om5e:
nStartPos = input.readLong(); rr4 _8Rf
nEndPos = input.readLong(); -W6V,+of
} hhj ,rcsi
input.close(); J{x##p<F$
} cuNq9y;[
catch(IOException e){e.printStackTrace ();} >rRjm+vg
catch(Exception e){e.printStackTrace ();} )#mW7m9M#
} !$XO U'n
1W7 iip,
98ayA$
private void processErrorCode(int nErrorCode) cWc$yE'
{ t5A[o7BS
System.err.println("Error Code : " + nErrorCode); /gF]s_
} BDnBBbBrz
EyPy*_A
i&5!9m`Cw
//停止文件下载 9Mut p4#
public void siteStop() nFVbQa~
{ 14;Av{Xt
bStop = true; '9Qd.q7s|b
for(int i=0;i<nStartPos.length;i++) GMyoSe%1/
fileSplitterFetch.splitterStop(); Q.uR<C6)v
Ic_tc
,Zr YJ<
} WVsKrFZT
} tTE3H_
//负责部分文件的抓取 n*Q4G}p
**FileSplitterFetch.java _i#@t7
*/ Mj,2\ijNM
package NetFox; P'gT6*an,"
v3!byN^
jCam,$oE
import java.io.*; fCs\Q
import java.net.*; [v~Uy$d\
dcM+ylB
Z,(%v.d
public class FileSplitterFetch extends Thread { 0FN~$+t)H
]Oig..LJ
d+1L5}Jn
String sURL; //File URL +}`p"<'u
long nStartPos; //File Snippet Start Position ?Of{c,2 .
long nEndPos; //File Snippet End Position av7q>NEZ!1
int nThreadID; //Thread's ID v] W1F,u
boolean bDownOver = false; //Downing is over GR_p1 C\
boolean bStop = false; //Stop identical k-;.0!D^
FileAccessI fileAccessI = null; //File Access interface o&*1U"6D
{Nzmb|&
P]{B^,E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xu0;a
{ Y+}OClS
this.sURL = sURL; 5mDVFb 3a
this.nStartPos = nStart; ]i9H_K
this.nEndPos = nEnd; aEV|>K=6Y'
nThreadID = id; M^0w/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *#3voJjV(
} b0rt.XB
Z5{*? 2
|F8;+nAVF#
public void run() 1"*Nb5s
{ WXRHG)nvL
while(nStartPos < nEndPos && !bStop) {[H4G,QK
{ \5j22L9S
Q'>_59
'|h./.K
try{ P6.)P|n7=
URL url = new URL(sURL); rHA/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Hv*^Bak
httpConnection.setRequestProperty("User-Agent","NetFox"); (UbR%A|v;
String sProperty = "bytes="+nStartPos+"-"; Q-H=wJ4R
httpConnection.setRequestProperty("RANGE",sProperty); 7"h=MB_
Utility.log(sProperty); ^F;Z%5P=
\H"/2o%l")
Oi+Qy[y2
InputStream input = httpConnection.getInputStream(); Y)@oo=oG
//logResponseHead(httpConnection); =[v2
s\F EA"w/
1o"y%*"
byte[] b = new byte[1024]; LRfFn^FPM
int nRead; /It.>1~2@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FE^?U%:u@
{ D0,oml
nStartPos += fileAccessI.write(b,0,nRead); }bj,&c
//if(nThreadID == 1) )w3XN A_V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i2\\!s
} &kmd<
/cn/[O9
3P=Eb!qtdD
Utility.log("Thread " + nThreadID + " is over!"); Wb*T
bDownOver = true; 6c;?`C
//nPos = fileAccessI.write (b,0,nRead); 'T#<OR
} (STWAwK-
catch(Exception e){e.printStackTrace ();} g&5pfrC [
} _s*uF_:3
} hx2!YNx !
PHE;
&~D.")Dz
//打印回应的头信息 Nys'4kx7
public void logResponseHead(HttpURLConnection con) z}Mb4{d1
{ & Q|f*T
for(int i=1;;i++) iZVT% A+q
{ ;]8p:ME
String header=con.getHeaderFieldKey(i); HY%6eUhj
if(header!=null) PN)TX~}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U:T5o]P<
Utility.log(header+" : "+con.getHeaderField(header)); b(.o|d/P
else SOi(5]
break; ~ 33@H
} t9=|* =;9)
} RvgAI`T7$
=*U%j
mF$jC:Tb
public void splitterStop() d/-0B<ts
{ @)!1#^(}%
bStop = true; ?!Th-Cc&m
} tpy:o(H
}lQn]q
n"`SL<K1
} ~[bMfkc3
G~mB=]
El8.D3
/* P^d.,
**FileAccess.java lk *QV
*//文件访问(定位，写) +{l3#Y
package NetFox; #,|_d>p:
import java.io.*; O(WMTa'%
EJSgTtp2
5{x[EXE'
public class FileAccessI implements Serializable{ WZy6K(18"'
P.2.Ge|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B39PDJ]hu
RandomAccessFile oSavedFile; {)dEO0 p
long nPos; 4UX]S\X
p%YvP
+~v3D^L15
public FileAccessI() throws IOException 4s+J-l
{ TVEF+t
this("",0); 8Jly!=Qm5
} +cplM5X
L"zgBB?K6
e]y=]}A3{
public FileAccessI(String sName,long nPos) throws IOException 8G^B%h]
{ qI/r_
oSavedFile = new RandomAccessFile(sName,"rw"); :."n@sA@
this.nPos = nPos; l Ib>t
oSavedFile.seek(nPos); <`VJU2
} k-Hfip[ro
sMe~C>RD
:!it7vZ
public synchronized int write(byte[] b,int nStart,int nLen) +^% &8<
{ 9#$V1(}?
int n = -1; o dQ&0d
try{ :?of./Df|
oSavedFile.write(b,nStart,nLen); WaZ@
n = nLen; w<^2h}5
} ]NhWhJ:
catch(IOException e) n;T
{ V%KW[v<G<
e.printStackTrace (); UBk 5O&
} wQ/@+$>
fw~%^*
z_iyuLRdb
return n; /iJhCB[QZ
} ?ia[KLt"
m_O=X8uj"D
'MM~~:
} Q9'V&jm
l\l]9Z6%
L08;z
/* VDI S`E
**SiteInfoBean.java lNp:2P
*/ [g 68O*
package NetFox; ` vmk
Ta5iY }
)k<~}wvQ0
public class SiteInfoBean { {*P7)
TKutO0
MM)/B>cQt
private String sSiteURL; //Site's URL F$.s6Hh.
private String sFilePath; //Saved File's Path tf}Q%)`f
private String sFileName; //Saved File's Name :zy'hu;
private int nSplitter; //Count of Splited Downloading File thboHPml{
nf@u7*#6
`U>b6{K
public SiteInfoBean() !(AFT!
{//nSplitter的缺省值为5 MvwJ(3
//default value of nSplitter is 5 -(,6w?
this("","","",5); K`Zb;R X
} G6ES]
p:n^c5
&ZFAUE,[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /M c"K
{ ~G^doj3|+
sSiteURL= sURL; F[giq1#
sFilePath = sPath; D`@U[`Sw
sFileName = sName; g<5Pc,
this.nSplitter = nSpiltter; [ESs?v$
aV%rq9Tp
|(8h:g
} "TNUw&ih
.T>}O0L"
*X55:yha
public String getSSiteURL() G~L#vAY
{ ^\9G{}VY
return sSiteURL; . zMM86c
} t#{>y1[29
!d@`r1t
)/^$JYz
public void setSSiteURL(String value) H/I`c>Zn
{ e-av@a3
sSiteURL = value; Hjkgy%N
} u1Yp5jp^K
IYC#H}
c&W.slE6
public String getSFilePath() 7VBw@Rh
{ 7anpz%
return sFilePath; dNt|"9~&
} c324@o^V
&Rt]K
#IwB
public void setSFilePath(String value) 2= mD
{ 6b)UoJxj
sFilePath = value; muq|^Hfb
} @S:/6__
zQ_[wM-
$q+`GXc-
public String getSFileName() ^*W<$A_
{ aRP+?}b">
return sFileName; hjT1SW\I
} UL"3skV
1"6k5wrIA
[63;8l}
public void setSFileName(String value) .ai9PsZ?V
{ (}8 ;3pp
sFileName = value; K)@Buu&,p
} tAi9mm;k
: seL=
B+sqEj-
public int getNSplitter() <}1%">RA
{ 7y7y<`)I5
return nSplitter; :_zKUv]
} .?j8{>
+yI^<BH
m~B=C>r}t
public void setNSplitter(int nCount) DNe^_v)]|
{ Ee&$9 )t
nSplitter = nCount; { "c,P:S]
} __c_JU
} #OTsD+2Za=
o>tT!8rH
eP?|U.on
/* &Hxr3[+$
**Utility.java *p!dd?8
*/ Z`KmH.l!
package NetFox; N|LVLsK
S7Fxb+{6D
vsR ^aVwVZ
public class Utility { bb/MnhB
A'EA!
<`qo*__1
public Utility() Fgk/Ph3r
{ ,;18:
BI]t}7
d`/{0:F
} XQ+hTtP
-9"Ls?Cu
//线程睡眠 |L&V-f&K
public static void sleep(int nSecond) 3MVZ*'1QM\
{ I,;)pWX=@
try{ )O Cr6UR
Thread.sleep(nSecond); t |hmEHUk
} bwFc>{Wo5
catch(Exception e) !Ua#smZ
{ u<zDZ{jt)
e.printStackTrace (); 78-:hk
} -~k2Gy;E
} '*;rm*n
~s_$a8
//日志 ^B9wmxe
public static void log(String sMsg) 3!L)7Z/
{ 'c D"ZVm1
System.err.println(sMsg); 8<xy*=%
} ffVYlNQ7L
!%@{S8IP.v
Gov{jksr
public static void log(int sMsg) B!v1gh
{ QPEv@laM
System.err.println(sMsg); d6VKUAk'7>
} ;}qCIyuO]
} +h/$_5
ijB,Q>TgO
`h'^S,'*
/* 2LdV=ifq2S
**TestMethod.java ngjbE+
*/ RFdN13sJv
package NetFox; M~IiJ9{
u4'Lm+&O
\ck3y]a[
public class TestMethod { 6eD[)_?]y
67eo~~nUtg
L"a#Uu8
public TestMethod() 4o8!p\a
{ ///xx/weblogic60b2_win.exe 8] *{i
try{ ? 6l::M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :jPAA`,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T9^i#8-^
SiteFileFetch fileFetch = new SiteFileFetch(bean); N\?iU8w=
fileFetch.start(); Y>+D\|%Q
} c#DTL/8"DO
catch(Exception e){e.printStackTrace ();} ZU|nKt<GK
:Us-^zVr
itU01
} l O^h)hrR
QWkw$mcf
k<qQ+\X
public static void main(String[] args) MqqS3
{ a#1X)ot
new TestMethod(); AN;?`AM;
} WA/\x
} @'<|B. f
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