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)); J%lgR
} Q Fm|-j
for(int i=0;i<nEndPos.length-1;i++) \55VqGyxu9
{ (~~w7L s
nEndPos = nStartPos[i+1]; @=jWHS
} kX`[Y@nUN
nEndPos[nEndPos.length-1] = nFileLength; /Ci*Az P
} vQ}6y
} 1 rs&74-
BQH}6ueZ
s*/bi W
//启动子线程 J(4"S o_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $j}OB6^I
for(int i=0;i<nStartPos.length;i++) j^tW Iz
{ 2dp>Z",
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uc7Eq45
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9^FziM
nStartPos,nEndPos,i); ZK;zm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SP*fv`
fileSplitterFetch.start(); CIU1R;
} mrIh0B:`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m%;D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W14F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *Xo]-cKL0
nEndPos = " + nFileLength); )SryDRT
// fileSplitterFetch[nPos.length-1].start(); c~QS9)=E
0:0NXVYs&
css64WX^0c
//等待子线程结束 K~=UUB
//int count = 0; 6DG@?O
//是否结束while循环 9O{b]=>wq
boolean breakWhile = false; @%k}FL=:t(
Z6\+
nJ4pTOc
while(!bStop) (C4fG@n
{ jls-@Wl
write_nPos(); X\EVTd)@
Utility.sleep(500); 3rLTF\
breakWhile = true; rc&%m
su*Pk|6%
~{sG| ;/!*
for(int i=0;i<nStartPos.length;i++) @36u8pE
{ Zo1,1O
if(!fileSplitterFetch.bDownOver) Ookh<ES>
{ 8-<:i
breakWhile = false; ifN64`AhRX
break; AJ#Nenmj
} {*{Ox[Nh{
} @(r/dZc
if(breakWhile) y.KO :P?5{
break; .bBdQpF-
\%UkSO\nO3
lHgs;>U$
//count++; quY:pqG38q
//if(count>4) vfVj=DYj
// siteStop(); Ft}@1w5
} h=;{oY<V)?
: ]C~gc
tcxcup%
System.err.println("文件下载结束！"); 2-Y<4'>
} /Q,mJ.CnSR
catch(Exception e){e.printStackTrace ();} MEB it
} SlsdqP 9
/SYw;<=
#g6.Glz3
//获得文件长度 8WnwQ%;m?
public long getFileSize() *z@>!8?
{ '7O3/GDK
int nFileLength = -1; lg^Z*&(
try{ !47n[Zs
URL url = new URL(siteInfoBean.getSSiteURL()); 1GzAG;UUo6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k:7(D_
httpConnection.setRequestProperty("User-Agent","NetFox"); -GxaV #{
W6Y]N/v3>
21"1NJzP
int responseCode=httpConnection.getResponseCode(); '-zD
if(responseCode>=400) 3Z1CWzq(
{ Y]&j,j&
processErrorCode(responseCode); K6R.@BMN
return -2; //-2 represent access is error 9T<x&
} =>-Rnc@
=?!wXOg_
#\=FO>
String sHeader; EN/,5<S<,[
rW$[DdFA5{
@;"|@!l|
for(int i=1;;i++) }}59V&'t
{ VVlr*`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -fDnA4;
//Utility.log(in.readLine()); q.;u?,|E/
sHeader=httpConnection.getHeaderFieldKey(i); &q9T9AOS
if(sHeader!=null) PUUwv_
{ n@)K #
if(sHeader.equals("Content-Length")) |:gf lseE
{ ]9^sa-8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %KLpig
break; 7j-4TY~
} E 7{U|\
} -qGa]a
else > ;*b|Ik
break; HAa;hb
} A6thXs2
} c24dSNJg,
catch(IOException e){e.printStackTrace ();} h'{ C[d
catch(Exception e){e.printStackTrace ();} r8RoE`/T
K &N
;~m8;8)
Utility.log(nFileLength); ]>5/PD,wWy
\"P%`C
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return nFileLength; u7>],<
} ig/xv
m;GCc8
Yi.N&&o
//保存下载信息（文件指针位置） *Q "wwpl?
private void write_nPos() kaVxT_
{ 4O^xY 6m
try{ -(;26\lE
output = new DataOutputStream(new FileOutputStream(tmpFile)); gCB |DY
output.writeInt(nStartPos.length); *`5.|{<j{
for(int i=0;i<nStartPos.length;i++) t-tg-<
{ c(xrP/yOwi
// output.writeLong(nPos); *0Skd
output.writeLong(fileSplitterFetch.nStartPos); 52Z2]T c,
output.writeLong(fileSplitterFetch.nEndPos); w;4<h8Wn5
} nFHUy9q
output.close(); ,/Z%@-rF
} ,is3&9
catch(IOException e){e.printStackTrace ();} W}@c|d $`
catch(Exception e){e.printStackTrace ();} qN9(S:_Px
} a%JuC2
V^bwXr4f
u}macKJmp\
//读取保存的下载信息（文件指针位置） 7x|9n
private void read_nPos() g}k`o!q
{ E Nhl&J
try{ vc;$-v$&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N/"{.3{W
int nCount = input.readInt(); l<58A7
nStartPos = new long[nCount]; /~%&vpF-L
nEndPos = new long[nCount]; FrGgga$
for(int i=0;i<nStartPos.length;i++) Bu~]ey1
{ 2lH&
nStartPos = input.readLong(); nv|NQ Tk
nEndPos = input.readLong(); |6sp/38#p
} $w`xvX
input.close(); Tztu}t]N
} _{YWXRC#
catch(IOException e){e.printStackTrace ();} l*(8i ^
catch(Exception e){e.printStackTrace ();} 8mvy\l EEH
} aFX=C>M
ZB= E}]v6
& p
private void processErrorCode(int nErrorCode) *5C7d*'
{ ;#W2|'HD
System.err.println("Error Code : " + nErrorCode); }c,}V
} C!<Ou6}!b
t6"%3#s
%HhnSi1K
//停止文件下载 l`lk-nb
public void siteStop() RB7tmJc
{ MS~(D.@ZS
bStop = true; A4x]Qh3OO
for(int i=0;i<nStartPos.length;i++) ]g3JZF-
fileSplitterFetch.splitterStop(); {I%cxQ#y
NZ:,ph
=7=]{Cx[
} _aSxc)?
} EHJ.T~X
//负责部分文件的抓取 g wRZ%.Cn
**FileSplitterFetch.java q 'yva
*/ WaRw05r
package NetFox; yS'I[l
\;Biq`
(=AWOU+
import java.io.*; <dtGK~_
import java.net.*; k(nW#*N_
Tx# Mn~xD
GR_-9}jQP
public class FileSplitterFetch extends Thread { &'`g#N
b{&)6M)zo
'o2Fa_|<#
String sURL; //File URL P/eeC"
long nStartPos; //File Snippet Start Position j3V -LnA
long nEndPos; //File Snippet End Position H/ HMm{4
int nThreadID; //Thread's ID EI%89i`3^
boolean bDownOver = false; //Downing is over S9y}
boolean bStop = false; //Stop identical =j]<t
FileAccessI fileAccessI = null; //File Access interface %J?xRv!
r#p9x[f<Y
QA`sx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QZ
{ j</: WRA`]
this.sURL = sURL; rq].UCj
this.nStartPos = nStart; U%QI a TN*
this.nEndPos = nEnd; Xl#ggub?
nThreadID = id; zTSTEOP}%Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AQvudx)@"
} k="i;! Ge
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hMO=#up&
public void run() hL{KRRf>
{ N~)_DjQP5
while(nStartPos < nEndPos && !bStop) .Yn_*L+4*
{ ?+@?Up0wGO
f.$af4 u
'zTLl8P
try{ 0S!K{xyR
URL url = new URL(sURL); .W!i7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zRr*7G
httpConnection.setRequestProperty("User-Agent","NetFox"); ]2KihP8z x
String sProperty = "bytes="+nStartPos+"-"; _]H&,</
httpConnection.setRequestProperty("RANGE",sProperty); S2&4g/
Utility.log(sProperty); sUQ@7sTj
/nA{#HY
bROLOf4S
InputStream input = httpConnection.getInputStream(); \_f(M|
//logResponseHead(httpConnection); T(Eugl"
?Z/V~,
9WyhZoPD*
byte[] b = new byte[1024]; 8<Av@9 *}
int nRead; fuySN!s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^<2p~h0 \
{ s.C_Zf~3
nStartPos += fileAccessI.write(b,0,nRead); )+DmOsH
//if(nThreadID == 1) 2P0*NQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EaN6^S=
} DB}eA N/
37o;;
[{,1=AB
Utility.log("Thread " + nThreadID + " is over!"); xwo<' xT
bDownOver = true; ,k3FRes3
//nPos = fileAccessI.write (b,0,nRead); 4,DeHJjAlE
} $>LQ6|XRu
catch(Exception e){e.printStackTrace ();} J)-x!y>
} vEJbA
} ^ [@,
vdwsJPFbc
.$vK&k
//打印回应的头信息 _oeS Uzq.
public void logResponseHead(HttpURLConnection con) E7hY8#G
{ 61U09s%\0
for(int i=1;;i++) WH^%:4
{ IH+|}z4N?>
String header=con.getHeaderFieldKey(i); UkFC~17P
if(header!=null) ,z=LY5_z)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qo|\-y-#
Utility.log(header+" : "+con.getHeaderField(header)); PCtzl)
else k!Y, 63V=
break; 7@W>E;go
} H<+TR6k<
} Xsa].
3!_XEN[
& 1f+,
public void splitterStop() dSHDWu&
{ AA>P`C$&M
bStop = true; 2D5StCF$O
} La[V$+Y
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]7A'7p$Y
} !j-Z Lq:;
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pd$[8Rmj_
/* "\yT7?},
**FileAccess.java 6_B]MN!(
*//文件访问(定位，写) 3Jn;}
package NetFox; 6ik$B
import java.io.*; o)/ 0a
"#g}ve,
:g/tZd$G5
public class FileAccessI implements Serializable{ gjlx~.0d
!5!<C,U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \Vk:93OH21
RandomAccessFile oSavedFile; Q+{n-? :
long nPos; c &c@M$
|DwZ{(R"W
:Hbv)tS\3w
public FileAccessI() throws IOException uXiN~j &Be
{ |I=T@1_D
this("",0); -yg7;ff
} `WS&rmq&'
"<gOzXpa
N2o7%gJw
public FileAccessI(String sName,long nPos) throws IOException *m(=V1"
{ dc'Y`e
oSavedFile = new RandomAccessFile(sName,"rw"); ^B^9KEjTz
this.nPos = nPos; }6ldjCT/,
oSavedFile.seek(nPos); Vjpy~iP4B
} n=q76W\
7xR\kL.,
G#$-1"!`
public synchronized int write(byte[] b,int nStart,int nLen) _yT Ed"$
{ '5tCz9}Y
int n = -1; ?V=CB,^
try{ Iu6
oSavedFile.write(b,nStart,nLen); 4^d?D!j
n = nLen; 0*v2y*2V
} XK vi=0B
catch(IOException e) cz$2R
{ T u'{&
e.printStackTrace (); :23P!^Y
} B-mowmJ3dg
}-2|XD%]
|':{lH6+1
return n; _"{Xi2@H
} 'N(R_q6MW
G+m }MOQP7
MqMQtU9w
} z(~_AN M4,
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moE2G?R
/* [N'h%1]\
**SiteInfoBean.java .]K%G\*`:
*/ VtohL+
package NetFox; h@BY]80
uw8f ~:LT
!`r$"}g
public class SiteInfoBean { )M^ gT}M
]_$[8#kg
47B&s
private String sSiteURL; //Site's URL 5-A\9UC*@
private String sFilePath; //Saved File's Path _VXN#@y
private String sFileName; //Saved File's Name "gwSJ~:ds
private int nSplitter; //Count of Splited Downloading File Yr|4Fl~U
!Z6{9sKR=]
o !7va"
public SiteInfoBean() <oeIcN7d
{//nSplitter的缺省值为5 2t,zLwBdnJ
//default value of nSplitter is 5 ,"ql5Q4
this("","","",5); cc34e
} K<J9~
DaVa}
LIrb6g&xj_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T^q 0'#/
{ sR8"3b<qA
sSiteURL= sURL; 3gf1ownC
sFilePath = sPath; g\AY|;T
sFileName = sName; M3Kfd
this.nSplitter = nSpiltter; {GUF;V ^
4GM6)"#d
,z?':TZ
} V43H/hl
)`}:8y?
y+;|Fz
public String getSSiteURL() R}ecc
{ !!ya
return sSiteURL; XfmwVjy
} Q@HV- (A
Y\tui+?J
!&\INl-Z
public void setSSiteURL(String value) tnIX:6
{ D`AsRd
sSiteURL = value; .e5Mnd%$M
} j|Q-*]V
C7?/%7{
et+0FF ,
public String getSFilePath() w#J2 wS
{ A)KZa"EX
return sFilePath; |K~Nw&rZ]
} ]%(2hY~i
y> (w\K9W
8>%hz$no=
public void setSFilePath(String value) (iGTACoF
{ ~{gqsuCCL
sFilePath = value; zMJT:7*`|
} Wez5N
Q=:|R3U/
BORA(,
public String getSFileName() U;I9 bK8
{ {:W$LWET
return sFileName; Vz[C=_m
} M:V_/@W.
F5#YOck&,
rQ9'bCSr%
public void setSFileName(String value) P>6{&(
{ k_R"CKd
sFileName = value; 'H!XUtFs"
} FgI3
l+0P
?hM64jI|
public int getNSplitter() (I}v[W
{ 59-c<I/}f
return nSplitter; ,2)6s\]/b
} lys#G:H]
c"xK`%e
|D.ND%K&
public void setNSplitter(int nCount) $wU\Js`/S]
{ {_dvx*M
nSplitter = nCount; %K QQ,{ b
} d5l UGRg
} QdC<Sk!G
W'.m'3#z
w*MpX U<
/* wdZ/Xp9]
**Utility.java PxE3K-S)G
*/ lHIM}~#;nd
package NetFox; 9k=3u;$v
v9UD%@tZ
:j`sr
public class Utility { Q5_o/wk
o`RKXfCq
o? $.fhD
public Utility() 6`-jPR
{ ,?XCyHSgWW
bYPKh
Ic4H#w
} .>nRzgo
8sCv]|cn
//线程睡眠 ],v=]+R
public static void sleep(int nSecond) {}Za_(Y,]
{ s|ITsz0,td
try{ b_):MQ1{
Thread.sleep(nSecond); xP,hTE
} jNy.Y8E&
catch(Exception e) V470C@
{ +t;7tQDVB
e.printStackTrace (); Xs?o{]Fe
} "wHFN>5B
} 8e|%M
:a)u&g@G
//日志 H7j0K~U0
public static void log(String sMsg) 4a]P7fx-
{ &! ?eL
System.err.println(sMsg); +d;bjo 2
} PiYxk+N
1sH& sGy7
V$?SR44>nH
public static void log(int sMsg) 8&aq/4:q0
{ k@:%:Sj 2
System.err.println(sMsg); Tu7QCr5*
} v}Fr@0%
} O8.5}>gDn.
"w.3Q96r
&`XVq"7
/* ?K\axf>F
**TestMethod.java @y&bw9\
*/ :08,JL{
package NetFox; }Z,x~G
XvlU*TO~(~
8ITdSg
public class TestMethod { #YOA`m,'
E\,-XH
?1eK#Z.
public TestMethod() Ue~CwFOc
{ ///xx/weblogic60b2_win.exe >oe]$r
try{ ^a1^\X.~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :[!j?)%>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); abLnI =W`
SiteFileFetch fileFetch = new SiteFileFetch(bean); xK\d4"
fileFetch.start(); \;"=QmRD%:
} f`=-US
catch(Exception e){e.printStackTrace ();} \} :PLCKT
*=7U4W
,nB5/Lx
} #ucBo<[
H DFOA
N'`A?&2ru
public static void main(String[] args) 1 Ya`| ?FS
{ w:Kl6"c
new TestMethod(); ]wG{!0pl
} NPe%F+X
} <HVt V9R
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