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)); NwdA@"YQ|
} @u2nG:FG
for(int i=0;i<nEndPos.length-1;i++) \ oIVE+L/P
{ }$ Am;%?p
nEndPos = nStartPos[i+1]; :d<;h:^_
} !%?X% @9
nEndPos[nEndPos.length-1] = nFileLength; WeTsva+
} &` u<KKF6
} ToN$x^M w
\Podyh/;?
^.J F?2T/
//启动子线程 b!ZXQn3X<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ODH@/
for(int i=0;i<nStartPos.length;i++) n(b(H`1n
{ (SLAq$gvd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~o+HAc`=v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e/m,PE
nStartPos,nEndPos,i); h+x"?^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8vM}moper
fileSplitterFetch.start(); {qCmZn5
} WKQVT I&A.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #<bt}Tht
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @hiwq7[j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <;.Zms${@
nEndPos = " + nFileLength); N}>XBZy
// fileSplitterFetch[nPos.length-1].start(); mlY0G w_e
8_K22]c5
Q+[e)YO)
//等待子线程结束 RTNUHz;{L
//int count = 0; ]cnLJ^2
//是否结束while循环 XnQo0 R.PW
boolean breakWhile = false; 0f 1Lu) 2
pCNihZ~
M ,8r{[2
while(!bStop) D!~-53f@
{ x(z[S$6Y\
write_nPos(); hp}J_/+4n
Utility.sleep(500); @U%I 6 t
breakWhile = true; ~n84x
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V$+xJ m
for(int i=0;i<nStartPos.length;i++) z.:{
{ JI}(R4uV
if(!fileSplitterFetch.bDownOver) o)7gKWjujP
{ s!09Pxc
breakWhile = false; pAYH"Q6~)I
break; dvk?A$
} 4?X#d)L(
} . oUaq|O
if(breakWhile) ZN|DR|cUY
break; qbkvwL9
%,GY&hTw
SU9#Y|I
//count++; \CL |=8[2
//if(count>4) cX@~Hk4=\
// siteStop(); k=O2s'F`
} )kl| 5i
Mu18s}
3mgFouX2x,
System.err.println("文件下载结束！"); "';'*x
} zqqpBwk#
catch(Exception e){e.printStackTrace ();} 5,'?NEyw
} [SgP1>M
/J8AnA1
86~HkHliv
//获得文件长度 jNV2o
public long getFileSize() 'z2}qJJ)
{ W?G4\ubM3<
int nFileLength = -1; abUn{X+f~
try{ l'VgS:NT
URL url = new URL(siteInfoBean.getSSiteURL()); ]6</{b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V{fYMgv
httpConnection.setRequestProperty("User-Agent","NetFox"); BUv;BzyV
3Qe:d_
>/EmC3?b!
int responseCode=httpConnection.getResponseCode(); 9tXLC|yl?
if(responseCode>=400) *"0Yr`)S
{ pK4I?=A'
processErrorCode(responseCode); L._I"g5 H9
return -2; //-2 represent access is error Y*O7lZuF%
} S)z jfJR
,:QG%Et
[bJ/$A
String sHeader; e%j+,)Ry
:KZI+
;k/y[ x}
for(int i=1;;i++) ^v3ytS
{ 1^R@X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~o%|#-S
//Utility.log(in.readLine()); 6!/e_a
sHeader=httpConnection.getHeaderFieldKey(i); +GgWd=X.Y
if(sHeader!=null) ji`N1e,l
{ g||{Qmr=1
if(sHeader.equals("Content-Length")) ,>2ijk#
{ EKk~~PhW 8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n w @cAv
break; e6k}-<W*q
} FgNO#%
} _$0<]O$
else jwTb09
break; D*`|MzlQ
} PX[taDN
} c}Y(Myd
catch(IOException e){e.printStackTrace ();} UMo=bs
catch(Exception e){e.printStackTrace ();} Qwk
oKz|hks[6
18Vtk"j
Utility.log(nFileLength); >c\'4M8Cz
OAR1u}
pQ*9)C
return nFileLength; U#+S9jWe
} WhSQ>h!@s
+XJj:%yt
u=jF\W9
//保存下载信息（文件指针位置） P`5@$1CJ
private void write_nPos() \)DP(wC
{ f$iv+7<B^
try{ FsY}mql
output = new DataOutputStream(new FileOutputStream(tmpFile)); vX)JJ|g
output.writeInt(nStartPos.length); 4/S4bk*8
for(int i=0;i<nStartPos.length;i++) q>%KIBh(
{ wtetB')yD
// output.writeLong(nPos); B=7bQli}
output.writeLong(fileSplitterFetch.nStartPos); 2JYyvJ>
output.writeLong(fileSplitterFetch.nEndPos); /Bid:@R
} . 3=WE@M
output.close(); OTL=(k
} {~k/xM.-
catch(IOException e){e.printStackTrace ();} ~LuZpV
catch(Exception e){e.printStackTrace ();} N/TUcG|m\
} s,"<+80%
nE+sbfC
0MF[e3)a
//读取保存的下载信息（文件指针位置） .Hl]xI$;+
private void read_nPos() bAeC=?U
{ yW^[{)V 3%
try{ =ILs[p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IaH8#3+a
int nCount = input.readInt(); C&,&~^_F
nStartPos = new long[nCount]; #!OCEiT_
nEndPos = new long[nCount]; ^vYH"2
for(int i=0;i<nStartPos.length;i++) ]=2Ba<)m
{ K\nN2y
nStartPos = input.readLong(); d47b&.v8e
nEndPos = input.readLong(); 5.]+K<:h"A
} vJ7I [Z
input.close(); E08FUAth]#
} "'4R_R
catch(IOException e){e.printStackTrace ();} uo_Y"QiKEH
catch(Exception e){e.printStackTrace ();} L|qQZ=
} Tw)nFr8oF]
`Ff3H$_*
kTAb <
private void processErrorCode(int nErrorCode) d `>M-:dF
{ Q$Ga.fI
System.err.println("Error Code : " + nErrorCode); JWr:/?
} bA@!0,m
tU>wRw=d
G6w&C^J*8>
//停止文件下载 A9Q!V01_
public void siteStop() 2^bq4c4J
{ |[CsLn;
bStop = true; xpxUn8.
for(int i=0;i<nStartPos.length;i++) <MB]W`5
fileSplitterFetch.splitterStop(); 9s6@AJf
II3)Cz}xRG
$/Gvz)M
} BDNn~aU#m
} P_B#
//负责部分文件的抓取 -/ ;y*mP
**FileSplitterFetch.java zu5'Ex`gQa
*/ h +.8Rl
package NetFox; Sav]Kxq{
M")JbuI
@H= d8$
import java.io.*; AMG}'P:
import java.net.*; ^I~2t|}
|Up+Kc:z/n
{^i73}@O
public class FileSplitterFetch extends Thread { S 3Tp__
9JBPE
.9 mwRYgD
String sURL; //File URL C<?}?hhb
long nStartPos; //File Snippet Start Position KoRJ'WW^
long nEndPos; //File Snippet End Position o%i^t4J$e
int nThreadID; //Thread's ID PBbJfm
boolean bDownOver = false; //Downing is over l9lBhltOH
boolean bStop = false; //Stop identical mM!'~{r[-
FileAccessI fileAccessI = null; //File Access interface jGl8y!aM
U s86.@|
K]Q#B|_T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException PEac0rSW
{ ];Z)=y,vM
this.sURL = sURL; <gF=$u|}3[
this.nStartPos = nStart; P9p:x6
this.nEndPos = nEnd; SUINV_>7
nThreadID = id; _G|hKk^,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6v(}<2~
} HYyO/U9z|I
X^ckTIdR
8W#/=Xh?
public void run() ?:vp3f#
{ 9un]}7^
while(nStartPos < nEndPos && !bStop) z}.y ?#
{ j5,1`7\7B
Umjt~K^Z
veAg?N<c p
try{ C8rD54A'M
URL url = new URL(sURL); I|9(*tq)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HS XS%v/Y
httpConnection.setRequestProperty("User-Agent","NetFox"); f]`#BE)V
String sProperty = "bytes="+nStartPos+"-"; n0F.Um
httpConnection.setRequestProperty("RANGE",sProperty); FRd!UqMXY
Utility.log(sProperty); (+68s9XS7
Ni#!C:q
id<i|
InputStream input = httpConnection.getInputStream(); SNV~;@(h
//logResponseHead(httpConnection); )Fx"S.Ok
11[[HkX@
reR><p
byte[] b = new byte[1024]; Tm(XM<
int nRead; #no~g(!o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fOJ0#^Z
{ zs e<b/G1G
nStartPos += fileAccessI.write(b,0,nRead); >J[Bf9)>
//if(nThreadID == 1) %KHO}gad1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >/mi#Y6
} D9,609w
{*,~,iq
hr_ 5D
Utility.log("Thread " + nThreadID + " is over!"); aDmyr_f$
bDownOver = true; 'kb5pl~U
//nPos = fileAccessI.write (b,0,nRead); mbB,j~;^6H
} T6m#sVq
catch(Exception e){e.printStackTrace ();} C~4_Vc*
} JBfDz0P
} mR@|]T
d0Xb?- }3M
TG7Ba[%
//打印回应的头信息 o`5p "v r
public void logResponseHead(HttpURLConnection con) ]Q,;5>#W
{ /_<`#?5T(
for(int i=1;;i++) 3[I; 3=O
{ _G%]d$2f`
String header=con.getHeaderFieldKey(i); HeABU(o4
if(header!=null) !>fYD8Ft,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yTzP{I
Utility.log(header+" : "+con.getHeaderField(header)); 5v <>%=
else A<P3X/i
break; bwo-9B
} _a1 =?
} $2B_a
^ CVhV
cpvN }G
public void splitterStop() /WlK*8C
{ nv&uhu/q
bStop = true; 1{+x >Pv:
} y6NOHPp@
ie|I*;#
fHhm)T8KB
} Atl`J.;G
:W]?6=
aEU[k>&
/* ]@X5'r"
**FileAccess.java z@;]Hy
*//文件访问(定位，写) e~R; 2bk
package NetFox; .{sKEVK
import java.io.*; *z[G+JX
XndGe=O
88}+.-3t$
public class FileAccessI implements Serializable{ >dKK [E/[d
b~DtaGh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [ []'U'
RandomAccessFile oSavedFile; PN9^ sLx=
long nPos; u.;zz'|
^kZfE"iE2
"<o[X ?u
public FileAccessI() throws IOException M S 3?#b
{ +Go(yS
this("",0); :$k':0 n
} =B4,H=7Spf
HUqG)t*c1
Oop5bg
public FileAccessI(String sName,long nPos) throws IOException VD[x}8ei
{ jv$Y]nf
oSavedFile = new RandomAccessFile(sName,"rw"); RtVy^~=G
this.nPos = nPos; r/v'h@
oSavedFile.seek(nPos); fxfzi{}uj
} r@C2zF7
#oRm-yDr
)E;+C2G
public synchronized int write(byte[] b,int nStart,int nLen) zogtIn)
{ Ow7NOhw
int n = -1; RC7|@a
try{ *Q2;bmIc
oSavedFile.write(b,nStart,nLen); C!Cg.^;
n = nLen; 9~+A<X]Hd
} E)==!T@E
catch(IOException e) n]M1'yU
{ \b{Aj,6,
e.printStackTrace (); u I$|M
} \zj _6Os
s_]p6M
$=dp)
return n; V]b1cDx{
} a*LT<N
YnnpgR.
gcYx-gA}
} csn/h$`-@
9pPb]v,6
p- 5)J&
/* ~wnTl[:
**SiteInfoBean.java &gJKJ=7
*/ }~P%S(zB
package NetFox; fDc>E+,
JFaxxW
8r '
public class SiteInfoBean { (;utiupW
[6x-c;H_4
;\`~M
private String sSiteURL; //Site's URL @|Z:7n6S
private String sFilePath; //Saved File's Path -r/G)Rs
private String sFileName; //Saved File's Name Hw"ik6
private int nSplitter; //Count of Splited Downloading File "|W .o=R
)6|7L)Dk
`(A6uakd
public SiteInfoBean() =PHl|^
{//nSplitter的缺省值为5 X!5N2x
//default value of nSplitter is 5 b i^h&H
this("","","",5); _`lj 3Lm0>
} g*b 4N_
9tZ)#@\
9xWC<i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KDwz!:ye
{ htc& !m
sSiteURL= sURL; \RN,i]c-g/
sFilePath = sPath; -_=0PW5{
sFileName = sName; MLg<YL
this.nSplitter = nSpiltter; pT]M]/y/:
&pwSd
iO=xx|d
} fr'M)ox1
s vn[c*
{#q']YDe`
public String getSSiteURL() 4GJ1P2
{ ={' "ATX(U
return sSiteURL; ~XGO^P"?
} a2W}Wb+
h"VQFqQy
Tks;,C
public void setSSiteURL(String value) {9TWPB/>
{ .4={K)kz|F
sSiteURL = value; *D`qcv
} 'G6TSl
[+$l/dag
Z:f0>
public String getSFilePath() Cpaeo0Oq
{ Vzy]N6QT{
return sFilePath; ?7-#iC`
} pM~Xh ]/
A2'
JV'd!5P
public void setSFilePath(String value) /=Ug}%.
{ Q0~5h?V'
sFilePath = value; M<JJQh5
} p>v,b&06
-Hzn7L
m%V+px
public String getSFileName() ZCPK{Ru QE
{ WrbDB-uM
return sFileName; J#Fe"
} }]vj"!?a
}@yvw*c
m}.ru)^p
public void setSFileName(String value) Hxr2Q]c?u
{ /R#-mY
sFileName = value; }yqRz6=YB
} J#*Uf>5NY
`7jm
THHrGvb
public int getNSplitter() :NU-C!eT
{ s#w+^Mw$
return nSplitter; Qo
} rh2pVDS
IWu^a w
i]GBu
public void setNSplitter(int nCount) !s,<hU#
{ c5P52_@
nSplitter = nCount; c?) pn9
} 6A M,1
} l^xkXj
qGkrG38K
~C5iyXR
/* $gDp-7
**Utility.java DHpU?;|3
*/ L5T)_iQ5
package NetFox; ^ vI|
R+]p -NI^
,r5<v_
public class Utility { r0G#BPgdR
d_J?i]AP|'
iMx+y5O
public Utility() B0=:A
{ mDE{s",q/
9BI5qHEp
4 E3@O
} ,2JqX>On>Y
~m!>e])P?X
//线程睡眠 !N$4.slr<p
public static void sleep(int nSecond) =D5@PHpv(
{ p@i U}SUaE
try{ X2@mQ&n
Thread.sleep(nSecond); \$;\,p p
} P@9>4}r$
catch(Exception e) 7g ]]>
{ ulfpop*2
e.printStackTrace (); .u7d
} S !c/"~X+
} ZC"6B(d
]+0-$t7Y
//日志 m?<8 ':
public static void log(String sMsg) R $'}Z
{ 3FPy"[[
System.err.println(sMsg); XeDU ,
} 3+A 0O%0*
t)XV'J
hD<z^j+
public static void log(int sMsg) ?d+B]VYw
{ |+6Z+-.Hg
System.err.println(sMsg); };oRx)
} zQ{ Q>"-
} ?]fBds=
7P/j\frW
IX7d[nm39
/* `RGZ-Q{_
**TestMethod.java ';aPoaO %
*/ x(}tr27o
package NetFox; I.x0$ac7
^%_B'X9
8YkP57Y%[Z
public class TestMethod { 74gU4T
H'gPGOd
L*FmJ{Yf
public TestMethod() gY0*u+LF
{ ///xx/weblogic60b2_win.exe |Q9S$l]
try{ 6FEtq,;0w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /oiAAB27
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JS(KCY9
SiteFileFetch fileFetch = new SiteFileFetch(bean); YD@V2gK
fileFetch.start(); tB(Q-c
} !c6lP'U
catch(Exception e){e.printStackTrace ();} 1<\cMY6
p00\C
Rp`}"x9
} bSz6O/A/
LV8,nTYvE
d,<ctd
public static void main(String[] args) !LIWoa[ F.
{ DP;B*s4{U
new TestMethod(); \!cqeg*53
} 8.-PQ
} aF'Ik XG d
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