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)); uDR(^T{g#
} L\I/2aiE
for(int i=0;i<nEndPos.length-1;i++) ~MF. M8
{ _nUuiB>
nEndPos = nStartPos[i+1]; (X/JXu{
} "^`AS"z'
nEndPos[nEndPos.length-1] = nFileLength; qS>el3G
} A\>qoR!Y
} R}FN6cH
X*@Sj;|m
1|--Xnv
//启动子线程 sKtH4d5)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tEl_A"^e
for(int i=0;i<nStartPos.length;i++) }<p%PyM
{ I]58;|J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Ok.XBS)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vHmn)d1pl
nStartPos,nEndPos,i); b.(^CYYQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7JbrIdDl|
fileSplitterFetch.start(); #%~wuCn<K
} u}$3.]-.?T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kmwFw>#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $v,_8{ !
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xp= ]J UQ
nEndPos = " + nFileLength); n7vi@^lf(
// fileSplitterFetch[nPos.length-1].start(); hdzaU&w
p6p_B
h1$,
//等待子线程结束 pB`<4+"9
//int count = 0; *P>F# ~X
//是否结束while循环 u56cT/J1
boolean breakWhile = false; c{[WOrA~#
K2JS2Y]
H|]Q;,C
while(!bStop) x\WKsc
{ ``{xm1GK
write_nPos(); GI/o!0"_
Utility.sleep(500); 70@:!HI]
breakWhile = true; bA:abO
SX#ATf6#
wXe.zLQ
for(int i=0;i<nStartPos.length;i++) CKK8 o9W
{ 1QThAFN
if(!fileSplitterFetch.bDownOver) =>9`qcNW_
{ {8eNQ-4I
breakWhile = false; _:J! |'
break; }QK-@T@4<
} o 0B`~7(
} B4%W,F:@
if(breakWhile) \RJ428sxn
break; "\30YO>\
[1Rs~T"
:0/I2:
//count++; ~~&M&Fe
//if(count>4) &0'BCT
// siteStop(); 0=NB[eG
} c(:GsoO
d4/ZOj+%
#-{4F?DA]y
System.err.println("文件下载结束！"); b$hQB090
} 'Q# KjY
catch(Exception e){e.printStackTrace ();} ].eGsh2
} V<b"jCXI
>5\rU[H>
j:g/[_0s
//获得文件长度 tq{ aa
public long getFileSize() rc"yEI-``"
{ /J^yOR9
int nFileLength = -1; O3S_P]{*ny
try{ yA~W|q(/V
URL url = new URL(siteInfoBean.getSSiteURL()); N7XRk=J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y:O%xtGi
httpConnection.setRequestProperty("User-Agent","NetFox"); g94NU X
Y`%:hvy~
YkTEAI|i
int responseCode=httpConnection.getResponseCode(); _95V"h
if(responseCode>=400) /IODRso/!
{ Xcb\N
processErrorCode(responseCode); {C [7V{4(%
return -2; //-2 represent access is error YQ&Xd/z-
} fU,sn5zZ
KdUmetx1
bx1'
String sHeader; DEIn:d
#8cY,%<S]
,`K'qms
for(int i=1;;i++) OX!9T.j
{ QM OOJA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n(&6E3ZcI
//Utility.log(in.readLine()); ;sDFTKf
sHeader=httpConnection.getHeaderFieldKey(i); Pl U!-7
if(sHeader!=null) I_4'9
{ P'[w9'B
if(sHeader.equals("Content-Length")) P7Kp*He)
{ Eg>MG87
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7^=O^!sa
break; 0EOpK%{
} bPWIf*3#
} -[Q%Vv!8
else &q>=6sQvf
break; 3eD#[jkAI;
} rk `x81
} B+ +:7!
catch(IOException e){e.printStackTrace ();} .Gw;]s3
catch(Exception e){e.printStackTrace ();} 't]=ps
D3$}S{Yw1
El,p}Bi.
Utility.log(nFileLength); \xwE4K
+c?1\{M
kP3'BBd,
return nFileLength; [/xw5rO%
} Iq MXd K|
to2dkU
G}d@^9FkE
//保存下载信息（文件指针位置） R["_Mff
private void write_nPos() s#>Bwn&b)
{ j*xxOwf
try{ {x s{
output = new DataOutputStream(new FileOutputStream(tmpFile)); k1W q$KCwG
output.writeInt(nStartPos.length); iXeywO2nP
for(int i=0;i<nStartPos.length;i++) 0@vSl%I+
{ r!'\$(m E
// output.writeLong(nPos); [;%qxAB/_
output.writeLong(fileSplitterFetch.nStartPos); 1t6VS3
output.writeLong(fileSplitterFetch.nEndPos); 5\lOZYHX
} mJp)nF8r~
output.close(); H1]G<N3
} &Nl:
catch(IOException e){e.printStackTrace ();} (bY#!16C:
catch(Exception e){e.printStackTrace ();} 7EO/T,{a
} s%GhjWZS
?"\X46Gz;
$ba3dqbCW
//读取保存的下载信息（文件指针位置） 1jO}{U
private void read_nPos() 6"b =aPTi
{ @Pb!:HeJE
try{ U:"E:Bxz;m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f 0D9Mp
int nCount = input.readInt(); _ 7X0
nStartPos = new long[nCount]; [kaj8
nEndPos = new long[nCount]; r$<[`L+6
for(int i=0;i<nStartPos.length;i++) %i:Sf
{ 8SR~{
nStartPos = input.readLong(); r&U5w^p
nEndPos = input.readLong(); F6`$5%$M;?
} 8K=sx@l
input.close(); l@Uo4b^4x
} Ep)rEq6
catch(IOException e){e.printStackTrace ();} $n.oY5=\
catch(Exception e){e.printStackTrace ();} XDRw![H,~
} M:YtW5{
Z(k7&^d
)OpB\k
private void processErrorCode(int nErrorCode) NBU[>P
{ \$LrL
System.err.println("Error Code : " + nErrorCode); 80DcM9^t8
} S2T~7-
!36jtKdM
gTa6%GM>
//停止文件下载 =^#^Mq)
public void siteStop() FwKT_XkY
{ {N!Xp:(<7_
bStop = true; ?VaWOwWI
for(int i=0;i<nStartPos.length;i++) lky{<jZ%
fileSplitterFetch.splitterStop(); K=nW|^
V~([{
N{w)}me[YY
} wC{?@h
} MZ]#9/
//负责部分文件的抓取 SkU'JM7<95
**FileSplitterFetch.java G;Jqby8d
*/ ]#x!mZ!
package NetFox; b+7!$
Y=94<e[f"
SFP%UfM<
import java.io.*; V 3?x_pp
import java.net.*; LVt{`
D; i%J
T$)N2]FE
public class FileSplitterFetch extends Thread { X} <p|P+
>,;, 6|S
F-0|&0
String sURL; //File URL `_M*2(rt
long nStartPos; //File Snippet Start Position W{'RR.
long nEndPos; //File Snippet End Position !0p_s;uu,W
int nThreadID; //Thread's ID [ed6n@/O@
boolean bDownOver = false; //Downing is over %+0 7>/
boolean bStop = false; //Stop identical 98O0M#|d
FileAccessI fileAccessI = null; //File Access interface ]w*w@:Zk
t{A/Lq9AM
gK7bP'S8H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException St 4YNS.|
{ yCC.j%@
this.sURL = sURL; u6tD5Y
this.nStartPos = nStart; !5FZxmUup
this.nEndPos = nEnd; ;]/>n:[E
nThreadID = id; g<d#zzP"T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A|Z'\D0
} oVDqX=G
u^5X@.
98"/]ERJ
public void run() [R-&5 G!x
{ GO3F[l
while(nStartPos < nEndPos && !bStop) dB`3"aSN7
{ Pi7IBz
E6 glR
-`knSR
try{ `GGACH3#s
URL url = new URL(sURL); k(As^'>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1"7Rs}l7
httpConnection.setRequestProperty("User-Agent","NetFox"); e&*< "WN
String sProperty = "bytes="+nStartPos+"-"; T;{M9W+
httpConnection.setRequestProperty("RANGE",sProperty); rwYlg:
Utility.log(sProperty); sA!,)'6
>M1m(u84#
kta`[%KmIZ
InputStream input = httpConnection.getInputStream(); t>]wWYy
//logResponseHead(httpConnection); ~_|OGp_a
~ 8hAmM
;ndsq[k>
byte[] b = new byte[1024]; <Vu/6"DP
int nRead; z^xrB$8 u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <]9%Pm#X
{ =~7%R.U([e
nStartPos += fileAccessI.write(b,0,nRead); Jng,:$sZ
//if(nThreadID == 1) ctqXzM `
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _hK83s4
} 5 *w a
qQzf&"
"otks\I<
Utility.log("Thread " + nThreadID + " is over!"); {Vg8pt
bDownOver = true; gtizgUS7
//nPos = fileAccessI.write (b,0,nRead); iPnu *29
} f[}N
catch(Exception e){e.printStackTrace ();} n4* hQi+d
} \(m_3 H
} y}TiN!M
{i}z|'!
kZ^}
//打印回应的头信息 g8I=s7cnb
public void logResponseHead(HttpURLConnection con) y:\ ^[y IQ
{ zQ[g*
for(int i=1;;i++) )qi/>GR,
{ !%pY)69gv
String header=con.getHeaderFieldKey(i); +s(JutC
if(header!=null) 4s{_(gy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y]z^e\qc)
Utility.log(header+" : "+con.getHeaderField(header)); aqa%B
else lz=DP:/&
break; &PfCY{_
} z?a<&`W
} 0H|U9
ve#*qz Y
lP9XqQ(
public void splitterStop() iymOq9
{ W`$D*X0*o
bStop = true; |(mr&7O
} -]!m4xvK
v7;zce/~
,}9G|$
} *)PCPYB^
(6Ssk4
%j '_I\
/* >,ThIwRN
**FileAccess.java +@:$7m(V
*//文件访问(定位，写) #1>DV@^F
package NetFox; .iDxq8l
import java.io.*; vSu|!Xb]
pt`^4}
uydy[n\
public class FileAccessI implements Serializable{ 2(s+?n.N
IV"OzQONx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^>?E1J3u
RandomAccessFile oSavedFile; s|/m}n
long nPos; sk0N=5SB-
D/T&0
mY}_9rTn|
public FileAccessI() throws IOException +Xb )bfN
{ dMcCSwYh
this("",0); bzI!;P1&
} zvvF9
3 #fOrNU2
zw13Tu
public FileAccessI(String sName,long nPos) throws IOException jGM+
{ \,U#^Vr
oSavedFile = new RandomAccessFile(sName,"rw"); f?-=&||f78
this.nPos = nPos; P>*g'OK^!G
oSavedFile.seek(nPos); lkj^<%N"r
} Q}a, f75
\ 2cI=Qf
RoL5uha,l
public synchronized int write(byte[] b,int nStart,int nLen) M"q]jeaM
{ =44hI86
int n = -1; vcsrI8+
try{ xB&kxW.;
oSavedFile.write(b,nStart,nLen); H9c
n = nLen; }~8/a3
} A578g
catch(IOException e) c&A;0**K,
{ --ED]S 8
e.printStackTrace (); 5&&6e`
} $On
/}_OCuJJ,
-jBk
return n; fS( )F*J
} ?,dbrQ
@;T>*_Yhn
RVlAWw(
} |FF"vRi8a7
Z*/*P4\
f87>ul!*
/* 'rT@r:6fn
**SiteInfoBean.java c*O{?b
*/ c1v,5c6d j
package NetFox; 1|_8+)i;
Dv7/eRt
s_(%1/{
public class SiteInfoBean { uYh6q1@"~
gk%8iT
8,E#vQ55}(
private String sSiteURL; //Site's URL d+9T}? T:*
private String sFilePath; //Saved File's Path ,zCrix 3
private String sFileName; //Saved File's Name u )'l|Y
private int nSplitter; //Count of Splited Downloading File P#_8$#G3
njz:7]>e
Tk9/1C{8
public SiteInfoBean() M4;A4V=W
{//nSplitter的缺省值为5 z0@)@4z!
//default value of nSplitter is 5 In-W,
this("","","",5); V;b^b5yZ>
} _g%Wx?K9
ELx?ph-9
m?Gb5=qo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A+JM* eB
{ MoKGnb
sSiteURL= sURL; G4!$48
sFilePath = sPath; $EHnlaG8r
sFileName = sName; yIS.'mK
this.nSplitter = nSpiltter; ;l]OmcL
|+?ABPk"
=y3gnb6
} w|6;Pf~1y)
0:W*_w0Ge
d|,,,+fS
public String getSSiteURL() :#M(,S"Qq
{ UX-l`ygl
return sSiteURL; 8]DN]\\o
} mp_(ke
|"[[.Adw9"
By3/vb)M5
public void setSSiteURL(String value) 5 =Os sAr
{ Zi+>#kDV
sSiteURL = value; ~I0I#_$'P
} b;!oPT
st;.Po[h
Fm\ h883\
public String getSFilePath() .uAOk0^z
{ NN<kO#c+2
return sFilePath; t7VXW{3
} N=) E$h
@@U'I^iG
>\Qyg>Md]
public void setSFilePath(String value) WMB~? EDhv
{ JwzA'[tM
sFilePath = value; "RuH"~o
} tS2P|fl
]xf lfZ
7y",%WYSD
public String getSFileName() xg~ Baun
{ MSPzOJQPy
return sFileName; K5x&:z
} #]G$o?@Y=^
ziuhS4k
H'uRgBjWJ
public void setSFileName(String value) 2?LZW14$d
{ ArBgg[i
sFileName = value; \h6_m)*H4
} e_6@oh2s-
U8?%Dq%i
W,zlR5+Jk
public int getNSplitter() Or&TGwo I
{ EP#3+BsH
return nSplitter; OQ<|XdI$
} $CaF"5}?Ke
6MfjB@
;4nz'9+
public void setNSplitter(int nCount) EthnI7Y
{ zosJ=$L
nSplitter = nCount; *Yk3y-
} w{[OtGIi3
} pCSR^ua>
EEQW$W1@
/}?"O~5M"
/* R1'bB"$
**Utility.java ]}/LNO*L"
*/ ;o;P2}zD
package NetFox; Mn(:qQo^&`
brN:Ypf-e
4LYeacL B
public class Utility { iARIvhfdi
pg69mKZ$
Qcu1&t\C
public Utility() P@'<OI
{ RE]u2R6Y
,.u7([SGm
s OD>mc#%Y
} _yTGv-
\p"`!n
//线程睡眠 b_*Y5"(*
public static void sleep(int nSecond) e:IUO1#
{ =!_e(J
try{ lz X0B&:
Thread.sleep(nSecond); f>nj9a5
} [3++Q-rR=
catch(Exception e) ZK))91;v
{ wmFI?
e.printStackTrace (); #5)E4"m
} "Ko^m(`
} bH+p5Fd;
> TG:}H(J
//日志 HT/zcd)}#
public static void log(String sMsg) ,Z*?"d
{ f.0~HnNg1
System.err.println(sMsg); mM"!=' z
} xZt]s3?
tWVbD%u^
gW'aK>*c
public static void log(int sMsg) ;X6FhQ;{*0
{ I,D24W4l
System.err.println(sMsg); G"0YCi#I|
} !+&"y K@J
} \{L!hAw
WE\912j
D`3m%O(?
/* {:c*-+?
**TestMethod.java YuD2Q{
*/ w\KO1 Ob
package NetFox; PgAC3%M6
YC4S,fY`
tUl#sqN_{
public class TestMethod { F*rU=cu
$O,$KAC
g@YJ#S(}
public TestMethod() AQ 3n=Lr
{ ///xx/weblogic60b2_win.exe zghUwW|K
try{ aoQK.7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C5#3c yf*B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p=jD "lq
SiteFileFetch fileFetch = new SiteFileFetch(bean); wI\v5&X-B
fileFetch.start(); 8C4DOz|
} QbqEe/*$_
catch(Exception e){e.printStackTrace ();} }X94M7+->
49&p~g
|lAu6d !
} r>4.{\C
jgbUZP4J>
,tv P"@d
public static void main(String[] args) fk,[`n+
{ =7ul,
new TestMethod(); fb[f >1|
} =ZjF5,@
} x3O$eKy\|5
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