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)); 4f@\f7\
} L8-[:1
for(int i=0;i<nEndPos.length-1;i++) :+dWJNY:
{ HV.|Eh_7
nEndPos = nStartPos[i+1]; ~bWWu`h
} Z$m2rZ#
nEndPos[nEndPos.length-1] = nFileLength; \qd)l
} pil*/&pB
} h C`p<jp/
B| 0s4E
j C1^>D
//启动子线程 4kY{X%9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e#eO`bT
for(int i=0;i<nStartPos.length;i++) d&R\7)0
{ rgvc5p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t;f p<z7N.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?[4khQt
nStartPos,nEndPos,i); s:Ql](/B#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r1[T:B'
fileSplitterFetch.start(); n)?F 9Wap
} o? xR[N-J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2T2#HP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WZ V*J&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .=w`T #L
nEndPos = " + nFileLength); Ckl]fy@D}
// fileSplitterFetch[nPos.length-1].start(); JU2' ~chh
wqoN@d
I:>d@e/;
//等待子线程结束 ]O(HZD%
//int count = 0; S?z j&XY3
//是否结束while循环 VA r?teY
boolean breakWhile = false; uKAHJ$%
Kmf-l*7}
WxP4{T* <
while(!bStop) ="TOa"Zk
{ jw%FZ
write_nPos(); #FDu4xi
Utility.sleep(500); P9cI{RI
breakWhile = true; *CD=cmdD*
h|>n3-k|p
0c;"bA0>Sx
for(int i=0;i<nStartPos.length;i++) o!dkS/u-m
{ (L
if(!fileSplitterFetch.bDownOver) DmpJzHj|
{ ,`2xfVa-
breakWhile = false; g$+O<a@n
break; ;8xn"G0}a
} `DY4d$!4
} OZ]3OL,
if(breakWhile) F^v{Jqc
break; >v4~:n2D
W)P_t"'@L
Vm8_ !$F
//count++; <YNPhu~5
//if(count>4) }Mlz\'{
// siteStop(); ]mU*Y:<
} LZbHK.G=
"'dC>7*<
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System.err.println("文件下载结束！"); ]CJ>iS!V
} (%IstR|u:
catch(Exception e){e.printStackTrace ();} H.S|njn:r
} ]vyF&`phb
'eXw`kw(
u=i^F|
//获得文件长度 b,V=B{(~
public long getFileSize() lxJ.h&"P
{ wDTV /"Y
int nFileLength = -1; (I 0t*Se
try{ 2F(\}%UT~
URL url = new URL(siteInfoBean.getSSiteURL()); _)H+..=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cmLu T/oV
httpConnection.setRequestProperty("User-Agent","NetFox"); _4#psxl[M
lMf5F8
, &f20o
int responseCode=httpConnection.getResponseCode(); )8>f
if(responseCode>=400) vK>^#b3
{ ] :#IZ0#
processErrorCode(responseCode); Mj;'vm7#'
return -2; //-2 represent access is error G7{:d
} H~K2`Cr)4
<NsT[r~C
l;FgX+)
String sHeader; R20GjWy=
~ a&j4E
bg. KkJMrR
for(int i=1;;i++) QI{Y@xQ
{ ! \Kh\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J4^cd
//Utility.log(in.readLine()); !@ '2
sHeader=httpConnection.getHeaderFieldKey(i); LBi>D`]
if(sHeader!=null) JKbB,
{ ^0~1/ PhOw
if(sHeader.equals("Content-Length")) ZDD|MH
{ fYPU'"hzG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v0J1%{/xs
break; _$lQK{@rY
} by[(9+/z$
} P &._-[
else wd0ACF
break; /;ITnG
} "Y0[rSz,UW
} |0%UM}
catch(IOException e){e.printStackTrace ();} Jxp'.oo[
catch(Exception e){e.printStackTrace ();} nuA!Jln_
J#WPXE+Ds
,i.P= o
Utility.log(nFileLength); _kLoDju%
wfzb:Aig`
]<= t
return nFileLength; sVnuSm
} 0g)mf6}o
#XPU$=
#| Po&yu4R
//保存下载信息（文件指针位置） e.H"!X!0#H
private void write_nPos() Xy<KvFy
{ R>q'Ymu~
try{ J[AgOUc
output = new DataOutputStream(new FileOutputStream(tmpFile)); l<6/ADuS
output.writeInt(nStartPos.length); Y{@[)M{<
for(int i=0;i<nStartPos.length;i++) %syBm
{ |Ay#0uQ5Y
// output.writeLong(nPos); }y/t~f+
output.writeLong(fileSplitterFetch.nStartPos); =@MKU
output.writeLong(fileSplitterFetch.nEndPos); ?xs0J
} !*-cf$
output.close(); :gtwvM7/B
} R[t[M}q
catch(IOException e){e.printStackTrace ();} ,#haai(
catch(Exception e){e.printStackTrace ();} V [>5
} 1vb0G;a;|
>o7k%T|l$
3!x)LUWfWY
//读取保存的下载信息（文件指针位置） )9->]U@
private void read_nPos() &YMj\KmlSg
{ (*]Y<ve
try{ hn.fX:}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n]!H,Q1,T
int nCount = input.readInt(); ~3 (>_r
nStartPos = new long[nCount]; t|lv6-Hy9
nEndPos = new long[nCount]; 5. i;IOx
for(int i=0;i<nStartPos.length;i++) 70~]J8T+u
{ N~(}?'y9S
nStartPos = input.readLong(); g9JtWgu
nEndPos = input.readLong(); tWuQKN`_
} qE[}Cf]X
input.close(); $Izk]o;X~
} _De;SB%V
catch(IOException e){e.printStackTrace ();} }Of^Y@{q.
catch(Exception e){e.printStackTrace ();} = '[@UVH(Z
} -6\9B>qa
k,,}N9
^ z;pP
private void processErrorCode(int nErrorCode) .v{ty
{ "mA/:8`Q
System.err.println("Error Code : " + nErrorCode); _QY "#
} lki(_@3
8:MYeE5
cW\7yZh
//停止文件下载 "+AD+D
public void siteStop() f?QD##~;
{ !Fi)-o
bStop = true; {Bx\Z0+'&
for(int i=0;i<nStartPos.length;i++) hSmM OS{
fileSplitterFetch.splitterStop(); gqG"t@Y+
>e%Po,Fg$
<V{BRRx
} Aj_}B.
} aUV>O`|_
//负责部分文件的抓取 ux=@"!PJ
**FileSplitterFetch.java S{ !hpq~o
*/ :gXj($
package NetFox; R.@GLx_zpQ
hS Sq=(S
9z#IdY$a
import java.io.*; NNX/2
import java.net.*; _>.%X45xi
cQjJ9o7
bc-"If Z&
public class FileSplitterFetch extends Thread { _"n4SXhq
Qk= w ,`
4p]Y`];U
String sURL; //File URL %{Gqhb=u\
long nStartPos; //File Snippet Start Position O1A*-G:X
long nEndPos; //File Snippet End Position i~4Kek6,I
int nThreadID; //Thread's ID S1."2AxO
boolean bDownOver = false; //Downing is over !?96P|G
boolean bStop = false; //Stop identical @47TDCr
FileAccessI fileAccessI = null; //File Access interface 7">.{ @S
x=k$^V~
Dqki}k~{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QnqX/vnR
{ ,=FYf|Z
this.sURL = sURL; Z6I!4K
this.nStartPos = nStart; H={,zZ11{
this.nEndPos = nEnd; -{?Rq'H
nThreadID = id; _v\QuI6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +x1sV*S
} I('l)^m%
]TQjk{X<
pw,.*N3P
public void run() (/^&3xs9
{ <]<50
while(nStartPos < nEndPos && !bStop) m~v Ie c
{ EpiagCS
|R4](
x/ez=yd*l
try{ *\>&
URL url = new URL(sURL); +{s^"M2`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (L\tp> E-
httpConnection.setRequestProperty("User-Agent","NetFox"); D4G{= Y}G
String sProperty = "bytes="+nStartPos+"-"; W\Gg!XsLk
httpConnection.setRequestProperty("RANGE",sProperty); -`( :L[
Utility.log(sProperty); nv={.H
Rj8l]m6U9
uzS57 O%
InputStream input = httpConnection.getInputStream(); *m;L.r`5[
//logResponseHead(httpConnection); eK`tFs,u
g$+3IVq&
Q{%ow:;s*
byte[] b = new byte[1024]; lm+wjhkN
int nRead; `bi5#xR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GRNH!:e
{ @{bf]Oc
nStartPos += fileAccessI.write(b,0,nRead); N7[~Y2i
//if(nThreadID == 1) &CS=*)>$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \"Np'$4eu
} *Hs5MXNu
Lczcz"t
:r\<DVj
Utility.log("Thread " + nThreadID + " is over!"); hAY_dM
bDownOver = true; [=iq4F'7
//nPos = fileAccessI.write (b,0,nRead); f"[C3o2P
} (Fu9lW}n
catch(Exception e){e.printStackTrace ();} d"V^^I)yx&
} _|F h^hq
} u+]zi"k^s
]$7|1-&Y
%T&kK2d;
//打印回应的头信息 MT3UJ6~P
public void logResponseHead(HttpURLConnection con) rC'97`!K
{ g}f@8;TY
for(int i=1;;i++) g,.iM8
{ wBr0s*1I
String header=con.getHeaderFieldKey(i); Z$q}y 79^
if(header!=null) Ay{4R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]WS 7l@
Utility.log(header+" : "+con.getHeaderField(header)); #PiW\Tq
else 6pH.sX$!_
break; 2nf{2edC
} Y,+$vj:y8
} )!0>2,R1
U+\\#5$
uG/Zpi
public void splitterStop() S2`p&\Ifn
{ GhX>YzD7
bStop = true; oRCj]9I$
} XX+4X*(o
^mH^cP?/
G-Y8<mEh
} Baq&>]
s01n[jQ
x]F:~(P
/* M]oaWQu
**FileAccess.java V ]Z{0
*//文件访问(定位，写) 1%>/%eyn5
package NetFox; 1"i/*}M
import java.io.*; .8k9yk
-cMqq$
q>,i `*
public class FileAccessI implements Serializable{ i7iL[+f]Q
9Y0w SOSW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <_h
RandomAccessFile oSavedFile; 9OX&;O+5
long nPos; ^W;\faG
?v6xaVg:
orJN#0v4
public FileAccessI() throws IOException h/5.>[VwDh
{ PKmr5FB
this("",0); oPl^tzO
} '};pu;GA7
h(ZZ7(ue
?8pRRzV$
public FileAccessI(String sName,long nPos) throws IOException m#ID%[hg$
{ usU5q>1
oSavedFile = new RandomAccessFile(sName,"rw"); | X! d*4
this.nPos = nPos; nzU^G)
oSavedFile.seek(nPos); "OkJPu2!W
} Nvw'[?m
!ouJ3Jn
sZ_+6+ :
public synchronized int write(byte[] b,int nStart,int nLen) Ubv<3syR'
{ 54v}iG
int n = -1; y$'(/iyz
try{ ApR>b%
oSavedFile.write(b,nStart,nLen); *{6{ZKM
n = nLen; xO{yr[x"L
} 5*C#~gd&F
catch(IOException e) (*F/^4p!$
{ ("?V|
e.printStackTrace (); ><^ ,
} O(#DaFJv
icH\(
^i:%0"[*^i
return n; qi!+Ceo}
} s9X?tWuL
WTbq)D(&[_
E&9BeU a#
} g{RVxGE7
VBo=*gn,$
C8ek{o)%W
/* DgW*Br8<
**SiteInfoBean.java Y'H|Tk^`
*/ P9c!
package NetFox; br`cxgZ0"
?NWc3 .
-Q9} gaH_
public class SiteInfoBean { d0YDNP%,_
muc6gwBp
lk;4l Z
private String sSiteURL; //Site's URL m7!Mstu
private String sFilePath; //Saved File's Path Qq+$ea?>
private String sFileName; //Saved File's Name Yv>kToa\^
private int nSplitter; //Count of Splited Downloading File OO#_0qK
y\k#83aU|
opqY@>Vh&
public SiteInfoBean() \SKobO?qI
{//nSplitter的缺省值为5 @L0xU??"|
//default value of nSplitter is 5 vY)5<z&
this("","","",5); u0p[ltJ,
} Ce_k&[AJF
qjDt6B^RO
-?nr q <3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O/ybqU\7
{ owQSy9Az
sSiteURL= sURL; }JI@f14
sFilePath = sPath; [0MNq]gxf
sFileName = sName; ?sD4S
this.nSplitter = nSpiltter; (P'{A>aHl0
bY&!d.
8n??/VDRl
} z*k(` '
h>k[
< #FxI
public String getSSiteURL() Nux
{ 4]G J+a
return sSiteURL; FJQ=611@
} Uhs/F:E[A
4Dy|YH$>S
*\gYs{,
public void setSSiteURL(String value) +cWo^d.
{ 18nT Iz_
sSiteURL = value; @k+K_gR
} O#MaZ.=
N1iP!m9Q
6U9FvPJ
public String getSFilePath() 1Be/(pSc
{ m941 Y
return sFilePath; vB<9M-sa0
} {:]u 6l
\Vb|bw'e(
q{Ao j
public void setSFilePath(String value) P"[\p|[U
{ owviIZFe
sFilePath = value; &ea6YQ
} DrK@y8
n{$! ]^>
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public String getSFileName() ,J(shc_F
{ Y6G`p
return sFileName; 3!M|Sf<s
} 'C7$,H'
eHb@qKnf
twMDEw#VL
public void setSFileName(String value) u+ b `aB
{ Z\r?>2
sFileName = value; O\F$~YQ
} go9tvK
Yz)+UF,
4OeH}@a
public int getNSplitter() v`hn9O
{ [>D5(O
return nSplitter; |"g+p)A
} R0~w F>
!LM9
}2h!
public void setNSplitter(int nCount) ~^bf1W[
{ BdrYc^?JL]
nSplitter = nCount; (<2!^v0.M
} ZiW&*nN?M
} i^@hn>s$
|@5G\N-
`*WzHDv5p
/* ^P|Zze zwU
**Utility.java }_=h]|6t
*/ NY?pvb
package NetFox; oP~%7Jt
\NZ@>on
$MqEM~^=
public class Utility { 6<fcG
\1sWmN6
n"w>Y)C(X)
public Utility() 0YZ66VN!
{ :{,k F
cs9"0&JX
ioBYxbY`
} ^+w1:C5
v:"Y
//线程睡眠 l}@C'Np
public static void sleep(int nSecond) 3aw-fuuIb
{ 9^7z"*@#
try{ 4k!>JQor
Thread.sleep(nSecond); |?v .5|1
} T9FGuit9
catch(Exception e) 2y IDyo
{ [>LO'}%
e.printStackTrace (); &r+!rL Kp
} *4/KK
} xFcW%m>9C
):\+%v^
//日志 5?A<('2
public static void log(String sMsg) `(r0+Qx
{ #+H3b!8=
System.err.println(sMsg); d*x&Uh[K
} .qLXjU
d ATAH}r&
[HhaBy9
public static void log(int sMsg) m2HO .ljc
{ >>c%Ic
System.err.println(sMsg); !yvw5As%
} @~&|BvK% \
} 1:RK~_E
tr58J%Mu
m=TZfa^r
/* Wo Z@
**TestMethod.java 5S[:;o
*/ x\IuM
package NetFox; k*OHI/uiow
IOa@dUh7a,
Wj8WT)cB
public class TestMethod { ^B8[B&K
v%kl*K`*
}zIWagC6
public TestMethod() )Y`ybADd3
{ ///xx/weblogic60b2_win.exe /]?e^akA
try{ i|0!yID0@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Fd1:"1pP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /8 yv8
SiteFileFetch fileFetch = new SiteFileFetch(bean); *TrpW?]Y&
fileFetch.start(); ~R\ $Z
} MAp#1+k
catch(Exception e){e.printStackTrace ();} ..x2
P'<j<h6
J\FLIw4
} oBs5xH7@-
G^Y^)pc]
)LsUO#%DO
public static void main(String[] args) %!DTq`F
{ .@\(ay
new TestMethod(); ]f5vk
} K+d{R=s^
} Xy}>O*
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