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)); ^fsC]9NS
} _g9j_ x:=
for(int i=0;i<nEndPos.length-1;i++) -DJ,<f*$
{ t~dK\>L
nEndPos = nStartPos[i+1]; x!W5'DO
} wj0_X;L
nEndPos[nEndPos.length-1] = nFileLength; \p}GW
} k >.U!
} k,'MmAz
0~_I9|FN
N"RPCd_
//启动子线程 XYD-5pG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b;*'j9ly
for(int i=0;i<nStartPos.length;i++) zsd<0^ p\{
{ 7&HcrkP]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \(=xc2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v9,cL.0&
nStartPos,nEndPos,i); |;(P+Q4lB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IO7gq+
fileSplitterFetch.start(); A /c
} k^ fW/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *' es(]W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q9VBK(,X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DzA'MX
nEndPos = " + nFileLength); htrtiJ1
// fileSplitterFetch[nPos.length-1].start(); eJn_gKWb
A7XA?>~+|
(RrC<5"
//等待子线程结束 D+ .vg?8
//int count = 0; Z eY*5m
//是否结束while循环 Ktt(l-e+
boolean breakWhile = false; )+Z.J]$O-
J4j:nd
z19%!k
while(!bStop) )h>dD
{ ]oz>/\!
write_nPos(); `-cw[@uD
Utility.sleep(500); x[)]u8^A
breakWhile = true; 9An\uH)mL
"X!1^)W-8
UUbO\_&y
for(int i=0;i<nStartPos.length;i++) D%?9[Qb
{ ~#VDJ[Z
if(!fileSplitterFetch.bDownOver) P*}aeu&lnD
{ khT[
breakWhile = false; 2*cc26o
break; #u+qV!4
} Y=_*Ai
} @q>#]8
if(breakWhile) xQzW6H|
break; lgK5E*^
FL^t}vA
&;r'JIp
//count++; 3m4 sh~
//if(count>4) n"}*C|(k
// siteStop(); bUM4^m
} ZdY$NpR,
Btr>ek
Hd7Vp:KM
System.err.println("文件下载结束！"); _akjgwu
} v+trHdSBYE
catch(Exception e){e.printStackTrace ();} t;PG
} 8'qlg|{!~
j"pyK@v2B
5! +{JTXa
//获得文件长度 .V}bfd[k$
public long getFileSize() =;Co0Q`
{ XhWo~zh"
int nFileLength = -1; =oiz@Q@H
try{ o$U{.#
URL url = new URL(siteInfoBean.getSSiteURL()); qe e_wx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3m-g-
httpConnection.setRequestProperty("User-Agent","NetFox"); p/7'r
UH+#Nel+!
zLg$|@E&
int responseCode=httpConnection.getResponseCode(); o /1+ }f
if(responseCode>=400) aMkuyqPf{
{ L\bcR
processErrorCode(responseCode); T$<'ZC
return -2; //-2 represent access is error h#)\K| qs
} i-p,x0th
hgDFhbHtd6
9jx>&MnWs
String sHeader; M$>Nd6,@N
z?kE((Ey
]:T:cO0_n
for(int i=1;;i++) y@2"[fo3~
{ U,fPG/9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +7 j/.R
//Utility.log(in.readLine()); Lc]hwMGR*
sHeader=httpConnection.getHeaderFieldKey(i); dN:^RCFzS
if(sHeader!=null) %gSmOW2.c^
{ QGGBI Ku
if(sHeader.equals("Content-Length")) Vu4LC&q
{ ePaC8sd0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U#PgkP[4
break; k,<7)-
} ]-a/)8
} [TqX"@4NS
else cG@Wo8+
break; Qz2jV
} jeA2yjAC
} YD9vWk\/
catch(IOException e){e.printStackTrace ();} 0Ny +NE:6M
catch(Exception e){e.printStackTrace ();} )#hR}|
@;{ZnRv14
{9j0k`A
Utility.log(nFileLength); x5;D'Y t"|
ZnRj}y
KiE'O{Y
return nFileLength; >Lo'H}[pF
} .A6pPRy e
9asA-'fZ
H0t#J
//保存下载信息（文件指针位置） 42,dHYdt
private void write_nPos() u%1JdEWZd
{ `jhbKgR[
try{ 4R8Qn^
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ic&YiATj
output.writeInt(nStartPos.length); --c)!Vxzx
for(int i=0;i<nStartPos.length;i++) LL+_zBP.
{ LtKR15h,
// output.writeLong(nPos); a%6=sqxE
output.writeLong(fileSplitterFetch.nStartPos); X2,v'`U5&
output.writeLong(fileSplitterFetch.nEndPos); )?l7I*
} ,qV7$u
output.close(); loBW#>
} )u]=^
catch(IOException e){e.printStackTrace ();} ZdPqU\G^q
catch(Exception e){e.printStackTrace ();} IC$"\7 @
} +~,q"6
gOE?
KZ65#UVX
//读取保存的下载信息（文件指针位置） gF293Ez
private void read_nPos() q%]5/.J
{ +R{~%ZTK
try{ w6lx&K-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VtU2&
int nCount = input.readInt(); M-+!z5q~d
nStartPos = new long[nCount]; P-yVc2YH
nEndPos = new long[nCount]; C+t|fSJ
for(int i=0;i<nStartPos.length;i++) d}Y#l}!E6
{ !Bg^-F:N
nStartPos = input.readLong(); ":=h1AJY
nEndPos = input.readLong(); b%C7 kL-
} GGZ9DC\{
input.close(); .]<gm9l
} ]1h9:PF
catch(IOException e){e.printStackTrace ();} I?\P^f
catch(Exception e){e.printStackTrace ();} v9f%IE4fX
} z`u$C+Ov
h+YPyeAs
!g|[A7<|
private void processErrorCode(int nErrorCode) '*&V7:
{ h{jm
System.err.println("Error Code : " + nErrorCode); W>b\O">
} fti0Tz'
}y(cv}8Y
KxFA@3
//停止文件下载 c2s73iz
public void siteStop() ]a*26AbU+
{ 20Jlf?
bStop = true; rCA0c8
for(int i=0;i<nStartPos.length;i++) ICG:4n(,
fileSplitterFetch.splitterStop(); pk;S"cnk
$t5>1G1j7
c7tO'`q$e
} Y10
} +I:/8,&-x
//负责部分文件的抓取 #a]\3X
**FileSplitterFetch.java ;uZeYY?
*/ ye}86{l
package NetFox; J~ *>pp#U
G#E8xA"{/
c% ?@3d
import java.io.*; 2J3y 1
import java.net.*; 3YUF\L]yyw
DwTVoCC
4JH^R^O<n
public class FileSplitterFetch extends Thread { Z`%^?My
VPVg\K{
+lf`Dd3
String sURL; //File URL wjOJn]
long nStartPos; //File Snippet Start Position c2Y\bKeN
long nEndPos; //File Snippet End Position e%7#e%1s
int nThreadID; //Thread's ID HA&hu/mw_
boolean bDownOver = false; //Downing is over ]\ZmK0q<:
boolean bStop = false; //Stop identical ,,S 2>X*L
FileAccessI fileAccessI = null; //File Access interface AJ#YjkO>]
H>-{.E1bG
(8NE'd8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@Wze[M?0
{ }p8iq
this.sURL = sURL; "412w^5[T
this.nStartPos = nStart; ,kFp%qNj
this.nEndPos = nEnd; Tx'anP
nThreadID = id; x69RQ+Vw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &$~irI
} yi-0CHo
:/>Zky8,k
_vAc/_N
public void run() ClPE_Cfw~
{ 52'6wwv6?
while(nStartPos < nEndPos && !bStop) }Cb-7/
{ T*(mi{[T
G) 37?A)
rfh`;G5s
try{ _ZK*p+u%
URL url = new URL(sURL); .rlLt5b%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "5\6`\/
httpConnection.setRequestProperty("User-Agent","NetFox"); }/L#<n`Z
String sProperty = "bytes="+nStartPos+"-"; nH+wU;M
httpConnection.setRequestProperty("RANGE",sProperty); 8>I4e5Ym
Utility.log(sProperty); od&wfwk(
%9L+ Q1o
_.m|Ml,`{
InputStream input = httpConnection.getInputStream(); 6_;n bqY&
//logResponseHead(httpConnection); [mG!-.ll
'PTQ S,E
5ne&6
byte[] b = new byte[1024]; dTwYDV}:
int nRead; fK^;?4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A":cS }Ui
{ v*OT[l7
nStartPos += fileAccessI.write(b,0,nRead); 2LCOB&-Ww
//if(nThreadID == 1) `j 4>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'W&ewZH_h
} CX]L'
]#'&x%m
ahN8IV=+Gm
Utility.log("Thread " + nThreadID + " is over!"); ;2aPhA
bDownOver = true; .k,,PuP
//nPos = fileAccessI.write (b,0,nRead); "z*?#&?,
} GgtYO4,
catch(Exception e){e.printStackTrace ();} Vf$$e)
} E>u U6#v
} VMu?mqEa
"9NWsy}<c
K}Q:L(SSr\
//打印回应的头信息 Fj`K$K?
public void logResponseHead(HttpURLConnection con) {_Fh3gjb/
{ Ia[<;":U
for(int i=1;;i++) mPo.Z"uy7
{ gzDfx&.0
String header=con.getHeaderFieldKey(i); |[)pQGw
if(header!=null) ?YF2Uc8z%2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z~;rp`P
Utility.log(header+" : "+con.getHeaderField(header)); K[Vj+qdyl
else {}H/N
break; ^SIA%S3
} vm=d?*cR
} \9R=fA18
=tGRy@QV'\
FA%V>&;`
public void splitterStop() UC.kI&A
{ 4)p ID`
bStop = true; -'^:+FU
} KppYe9?
2g5jGe*0
n.G.fbO
} A~<cp)E
z0|-OCmL
]VS:5kOj`
/* {f;DhB-jj
**FileAccess.java {"|la;*I
*//文件访问(定位，写) _]L]_Bh
package NetFox; Zlrbd
import java.io.*; D"IxQ2}k
)OK"H^}f
7zowvE?#
public class FileAccessI implements Serializable{ bR?xz-g%<3
f @Vd'k<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2dDhO
RandomAccessFile oSavedFile; *qFl&*h}
long nPos; #S[Y}-]T
UQbk%K2
x4v&%d=M
public FileAccessI() throws IOException lWUQkS
{ |*l^<==
this("",0); ~m[Gp;pL
} 1yFIIj:^|
G7r.Jm^q
b)r;a5"<5
public FileAccessI(String sName,long nPos) throws IOException l9&L$,=
{ LyG`q3@
oSavedFile = new RandomAccessFile(sName,"rw"); lcVG<*gf-
this.nPos = nPos; $v5 >6+-n
oSavedFile.seek(nPos); ~JP3C5q
} *]!rT&E
|+qsO;
!=u=P9I
public synchronized int write(byte[] b,int nStart,int nLen) gJ>#HEkMB
{ u~~ ~@p
int n = -1; Emw]`
try{ d<w]>T5VW
oSavedFile.write(b,nStart,nLen); gu&W:FY
n = nLen; |\94a
} n3$u9!|P
catch(IOException e) 3#eAXIW[
{ -vc ,O77z"
e.printStackTrace (); +x<OyjY5?]
} L^K,YlNBR
bgkBgugZhX
:m>Vp
return n; PzustC|
} 5f2=`C0_
\+:`nz3m
\ rKUPI\
} cg9*+]rc
=)a%,H
^)h&s*
/* +{#Z^y6&
**SiteInfoBean.java 9_~9?5PU
*/ ;j+*}|!
package NetFox; !/X>k{
\S{ihS@J
{Z178sik
public class SiteInfoBean { d<E2=WVB6
a%?v/Ku
q d:"LS
private String sSiteURL; //Site's URL b;NVvc(
private String sFilePath; //Saved File's Path fUPYCw6F
private String sFileName; //Saved File's Name c{qTVi5e
private int nSplitter; //Count of Splited Downloading File 8<@X=Z
qxYCT$1
s4Vju/
public SiteInfoBean() }vg|05L
{//nSplitter的缺省值为5 uO1^nK
//default value of nSplitter is 5 7p>T6jK)
this("","","",5); r>.l^U9hJ
} Qh*}v!3Jo
x'SIHV4M@Q
c5pK%I}O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5'%O]~
{ J/PK#<
sSiteURL= sURL; &%eM
sFilePath = sPath; 8?|W-rN
sFileName = sName; 9E|QPT
this.nSplitter = nSpiltter; ~RZN+N
6z'0fi|EN
77j"zr7v
} ?v'CuWS
735l&(3A\
%4BQY>O)@
public String getSSiteURL() ce719n$
{ "W_E!FP]r
return sSiteURL; xn)F(P 0kv
} j)Z0K$z=
\gv-2.,
)Lk2tvr
public void setSSiteURL(String value) k?/!`
{ dKL9}:oUa
sSiteURL = value; z80*Ylx
} /q/^B>]
Kek%io
tCGA3t
public String getSFilePath() P2U4,?_e
{ ?}EWfsA
return sFilePath; S&;)F|-q
} m}2hIhD9
X7gB.=\X
>y!O_@>z
public void setSFilePath(String value) Z&h:3;
{ 6F%6]n
sFilePath = value; $"#M:V@
} +aqQa~}r
B%o%%A8*g
=PnNett}a
public String getSFileName() !~j9Oc^
{ {96NtR0Z
return sFileName; Zjs,R{
} ]{I>HA5[
y{XNB}E
*$/Go8t4u
public void setSFileName(String value) $jBi~QqOf
{ {xP-p"?p
sFileName = value; *Tmqs@L
} gLx?0eBBA
.mOm@<Xdg
Oo ^AE
public int getNSplitter() !A14\
{ - 8jlh
return nSplitter; VRHS 4
} B =DV!oUg
.dvs&+I
R/6 v#9m7
public void setNSplitter(int nCount) >z,Y%A
{ R1.Yx?
nSplitter = nCount; 8-smL^~%#
} y;O 6q206
} n"R$b:
Lf{pTxKr
h,]lN'JG{
/* .RS
**Utility.java UY:Be8C A
*/ DYew6B-
package NetFox; dLf ;g}W
TBHd)BhI.
0 eOdE+
public class Utility { 'SIc2H
U)3?&9H
K5(T7S
public Utility() NCm=l
{ Yt r*"-
H 'nLC,
9mpQusM
} [yRqSB
[y<s]C6E
//线程睡眠 <FN+
public static void sleep(int nSecond) ](IOn:MuDE
{ #!rH}A>n+
try{ |6`7kb;p
Thread.sleep(nSecond); h5^We"}+
} Q"qJ0f)
catch(Exception e) f_:>36{1^!
{ >(sS4_O7N
e.printStackTrace (); N0ZD+
} :rvBx"
} /&!o]fU1C
TNcMrbWA
//日志 A\ tBmL_s
public static void log(String sMsg) I."s&]FZ
{ ycWY.HD
System.err.println(sMsg); u#->?
} qz!^< M
2J`LZS
2[KHmdgtB
public static void log(int sMsg) \ow(4O#
{ 4XeO^#
System.err.println(sMsg); ikPr>
} J/[PA[Rf
} %<h2^H\O
V.o*`V
J!'IkC$>
/* w *o _s
**TestMethod.java **ls 4CE<
*/ zXd#kw;
package NetFox; YIYuqtnSJ
e"2x!(&n(
u5,vchZ
public class TestMethod { d-]!aFj|U
=e6!U5 f
A}1:fw\Fn3
public TestMethod() #|Je%t}~
{ ///xx/weblogic60b2_win.exe [bN_0T.YI
try{ <H1e+l{8$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V("T9g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =1mIk0H`
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]oC7{OoX
fileFetch.start(); 'qidorT>N
} f{'NO`G
catch(Exception e){e.printStackTrace ();} b/=>'2f
?;go5f+X
h0VeXUM;.
} sWgzHj(c
/(i~Hpp
S'sI[?\x
public static void main(String[] args) ZXWm?9uw
{ o1Wf#Zq
new TestMethod(); G:MQ_tfr&
} |:d_IB@
} e#?rK=C?9
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