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)); cd~QGP_C
} i!fk'Yt%
for(int i=0;i<nEndPos.length-1;i++) {MN6JGb|'
{ YzJWS|]
nEndPos = nStartPos[i+1]; p.<d+S<
} :?}>Q
nEndPos[nEndPos.length-1] = nFileLength; h#Mx(q
} C?MKbD=K
} zlB[Eg^X
v9!]/]U^
*>!-t
//启动子线程 1H\5E~X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ted tmX$
for(int i=0;i<nStartPos.length;i++) <WbO&;%
{ S;/pm$?/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c,]fw2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s0CDp"uJY
nStartPos,nEndPos,i); Z%b1B<u$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]ncK M?'O
fileSplitterFetch.start(); U6o]7j&6
} 1vAJ(O{-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), + rM]RFi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &_s^C?x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6(7dr?^eGT
nEndPos = " + nFileLength); ;mr*$Iu7|
// fileSplitterFetch[nPos.length-1].start(); r[^O 7
8M,z#DF
6-\' *5r
//等待子线程结束 zGc]*R
//int count = 0; "uj@!SEs`?
//是否结束while循环 4/_!F'j
boolean breakWhile = false; 6JeAXj1g+
qVO,sKQ{
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while(!bStop) iA`.y9'2
{ 2f{a||
write_nPos(); KxBvL[/
Utility.sleep(500); xX0wn?,~
breakWhile = true; :c Er{U8
?%lfbZ
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for(int i=0;i<nStartPos.length;i++) pAaNWm
{ W6r3v)~
if(!fileSplitterFetch.bDownOver) b\kA
{ kIe)ocJg
breakWhile = false; &OkPO|
break; -s7!:MB%g
} ^4p$@5zH
} >wFn|7\)s>
if(breakWhile) 0QW;=@)d
break; ($8!r|g5#
4Me3{!HJz
)T&r770
//count++; 2z AxGX
//if(count>4) ;!7M<T$&
// siteStop(); -a"b:Q
} I47sqz7
*o!#5c
et(AO)uv6
System.err.println("文件下载结束！"); "ub0}p4V
} r^ '
catch(Exception e){e.printStackTrace ();} T[g(S0dz
} B5R7geC
?%D nIl>
Z^%HDB9^
//获得文件长度 0Pt%(^
public long getFileSize() (h[. Ie
{ cK\?wZ| Y
int nFileLength = -1; e5"5 U7
try{ v`Ja Bn
URL url = new URL(siteInfoBean.getSSiteURL()); ^X"x,8}&V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A!uiM*"W
httpConnection.setRequestProperty("User-Agent","NetFox"); Jp_ :.4
r Cz,XYV
tWQ$`<h
int responseCode=httpConnection.getResponseCode(); Qw"%Xk
if(responseCode>=400) (.wR!l#!
{ \NKw,`/
processErrorCode(responseCode); Q)8I(*
return -2; //-2 represent access is error H:WuMwD4
} {h.j6
dYlVJ_0Zr
dl`{:ZR S
String sHeader; 9A|9:OdG1
C}pQFL{B5
;<%th
for(int i=1;;i++) ~LP5hL
{ %F}d'TPx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F ^m;xy
//Utility.log(in.readLine()); ,Vof<,x0
sHeader=httpConnection.getHeaderFieldKey(i); k@gQY_
if(sHeader!=null) LW9F%?e!>
{ &]A0=h2{P*
if(sHeader.equals("Content-Length")) MlW*Tugg
{ g;7u-nP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tDMNpl
break; HXPq+
} R+=wSG]
} YTr+"\CkA
else am7~
break; yb0Mn*X+ N
} P{: 5i%qC
} N&|,!Cu
catch(IOException e){e.printStackTrace ();} gr# |ZK.`
catch(Exception e){e.printStackTrace ();} s3K!~v\L]
'tjqfR
k/BlkjlNE
Utility.log(nFileLength); lvLz){
p9S>H
c'5ls7?}O{
return nFileLength; 1S yG
} :YLurng/]
k[@/N+;")`
~]'yUd1gSZ
//保存下载信息（文件指针位置） gg Nvm
private void write_nPos() Yn0iu$;n
{ :-(qqC:
try{ %c8@
output = new DataOutputStream(new FileOutputStream(tmpFile)); +jKu^f6
output.writeInt(nStartPos.length); b&AeIU}&
for(int i=0;i<nStartPos.length;i++) .Sv/0&O
{ @18}'k
// output.writeLong(nPos); l 3 jlKB
output.writeLong(fileSplitterFetch.nStartPos); ,3!4 D^
output.writeLong(fileSplitterFetch.nEndPos); o,@(]e~
} Q-1Xgw!
output.close(); aY6F4,7/B
} %7?Z|'\
catch(IOException e){e.printStackTrace ();} 8`90a\t'Z
catch(Exception e){e.printStackTrace ();} zw iS%-F
} <|w(Sn
d"Zyc(Jk
c: (nlYZ
//读取保存的下载信息（文件指针位置） k^zU;
private void read_nPos() . lNf.x#u
{ EG3u)}vI
try{ Ynp#3r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _1~pG)y$U
int nCount = input.readInt(); Vjd>j; H
nStartPos = new long[nCount]; Tk`|{Ph0
nEndPos = new long[nCount]; vcaPd}nf
for(int i=0;i<nStartPos.length;i++) `}rk1rl6
{ K6|R ;r5e{
nStartPos = input.readLong(); 8NTE`l=>/
nEndPos = input.readLong(); Qd>\{$N
} /!`xqG#
input.close(); uf"(b"N0
} S6fbwZZMG
catch(IOException e){e.printStackTrace ();} o7eWL/1
catch(Exception e){e.printStackTrace ();} D'BGoVP
} ^MG"n7)X
SDVnyT
yM,Y8^
private void processErrorCode(int nErrorCode) D_`NCnYG
{ J"TF@7{p
System.err.println("Error Code : " + nErrorCode); X}g3[
} ,,BWWFg~
w6pXF5ur>
ff~1>=^
//停止文件下载 ~qK/w0=j
public void siteStop() \)ZCB7|
{ 9}H]4"f7
bStop = true; $+$l?2
for(int i=0;i<nStartPos.length;i++) p+dOw#
fileSplitterFetch.splitterStop(); (%"9LYv
IFhS(3YK[
c@J@*.q]
} ~@#a*="
} +d(|Jid
//负责部分文件的抓取 iq,rS"
**FileSplitterFetch.java e^$JGh2
*/ 15r=d
package NetFox; {w7/M]m-
1+YqdDqQ
R'" c
import java.io.*; (L(n%
import java.net.*; 8(L6I%k*
jx2{kK
14 (sp
public class FileSplitterFetch extends Thread { @7KG0<]h
8)ng> l
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String sURL; //File URL ;~'&m
long nStartPos; //File Snippet Start Position vhcp[=e :
long nEndPos; //File Snippet End Position M}Xf<:g)
int nThreadID; //Thread's ID [AA}P/iW
boolean bDownOver = false; //Downing is over VKf&}u/
boolean bStop = false; //Stop identical Lj3Pp$h
FileAccessI fileAccessI = null; //File Access interface M>}_2G]#F
Qkhor-f0
$48Z>ij?f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D3%2O`9
{ 1Kd6tnX
this.sURL = sURL; mrr~#Bb>
this.nStartPos = nStart; 1vtC4`
this.nEndPos = nEnd; 8m=O408Q
nThreadID = id; OmS8cSYGc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ncUS8z
} GR4DxlX
ZY@ntV?
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public void run() J0oeCb
{ P,F eF'J^
while(nStartPos < nEndPos && !bStop) -4P `:bF
{ kX8NRPW
mCG&=Fx
$L?KNXHAF!
try{ E+#<WK-
URL url = new URL(sURL); k%Vprc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S>S7\b'
httpConnection.setRequestProperty("User-Agent","NetFox"); =O-irGms*
String sProperty = "bytes="+nStartPos+"-"; (z?j{J
httpConnection.setRequestProperty("RANGE",sProperty); -'SA&[7dP
Utility.log(sProperty); #qpP37G
To5hVL<Ex"
Z*Gf`d:
InputStream input = httpConnection.getInputStream(); z?( b|v
//logResponseHead(httpConnection); ;BYuNQr
$mh\`
D9?.Ru0.
byte[] b = new byte[1024]; QWEE%}\3}
int nRead; Ak8Y?#"wz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ip:54
{ wy0?*)~
nStartPos += fileAccessI.write(b,0,nRead); #V%98|"
//if(nThreadID == 1) v(!:HK0oeT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YRFz]
} w( _42)v]g
u6Lx3
bI8uw|c
Utility.log("Thread " + nThreadID + " is over!"); ,isjiy J
bDownOver = true; S#$Kmm |
//nPos = fileAccessI.write (b,0,nRead); T~(Sc'8
} m}\QGtJ6
catch(Exception e){e.printStackTrace ();} aWJj@',_
} p:z~>ca
} o:fe`#t
RAP-vVh/C
CxZh^V8LP
//打印回应的头信息 l`i97P?/W
public void logResponseHead(HttpURLConnection con) G\TO]c
{ %^vT7c>
for(int i=1;;i++) 6a9$VGInU
{ d7 H*F
String header=con.getHeaderFieldKey(i); /XEW]/4
if(header!=null) JXYZ5&[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?Ve IlD
Utility.log(header+" : "+con.getHeaderField(header)); `fTM/"
else ,"XiI$Le
break; O#^H.B
} ?%}!_F`h%
} #/f~LTE
_#s,$K#
VqpC@C$
public void splitterStop() )1KyUQ\e
{ l-l7jq]R
bStop = true; V3cKbk7~
} nS*Y+Q^9a
% hvK;B?Y|
Jk6}hUH,
} %0N HU`j
W ';X4e
i>s
/* P <+0sh
**FileAccess.java )AQ^PBwp
*//文件访问(定位，写) _Uq' N0U
package NetFox; <.B+&3')
import java.io.*; $[n:IDa*@1
a4=(z72xe
X3X_=qzc
public class FileAccessI implements Serializable{ `+"(GaZ
y{>f^S<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gJ'pwSA
RandomAccessFile oSavedFile; eY5mwJ0K
long nPos; Xa?O)Bq.
ng"=vmu
?(R3%fU
public FileAccessI() throws IOException a[(OeVQ5
{ G~YZ(+V%~
this("",0); voRry6Q;
} EN2SI+
vjlN@ "
<78|~SKAV
public FileAccessI(String sName,long nPos) throws IOException _wS=*-fT
{ (^m] 7l
oSavedFile = new RandomAccessFile(sName,"rw"); 0f.jW O
this.nPos = nPos; <ak[`]
oSavedFile.seek(nPos); "J1A9|
} a3tcLd|7J
7upko9d/
hx$61E=
public synchronized int write(byte[] b,int nStart,int nLen) :Kwu{<rJ!(
{ <f>w"r
int n = -1; \7r0]& _
try{ Wye* ~t
oSavedFile.write(b,nStart,nLen); ]VRa4ZB{u
n = nLen; Qs6Vu)U=
} Nc7"`!;-
catch(IOException e) |Ev|A9J!
{ d8wVhZKI"
e.printStackTrace (); &uK(. @
} 6*q1%rs:w
^{4BcM7eH
=cS&>MT
return n; Mh.1KI[t
} 10Ik_L='
<\~v$=G
_SAM8!q4,
} ,X4+i8Yc
[-])$~WfW
w={q@. g%
/* o@e/P;E
**SiteInfoBean.java d_@ E4i
*/ Sfz1p
package NetFox; +[!S[KE
)8@-
j Q5F}
public class SiteInfoBean { zjQ746<&)i
73;Y(uh9
Q[biy{(b8
private String sSiteURL; //Site's URL L0fe
private String sFilePath; //Saved File's Path .B:ZyTI
private String sFileName; //Saved File's Name K381B5_h
private int nSplitter; //Count of Splited Downloading File -e/}DGL
!C#oZU]P
f+cb83}n]
public SiteInfoBean() QxYm3x5
{//nSplitter的缺省值为5 t0m;tb bg
//default value of nSplitter is 5 q? '4&
this("","","",5); "GO!^ZG]
} eU1F7LS
ez,.-@O
"?NDN4l*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /iU<\+ H
{ TTz=*t+D
sSiteURL= sURL; ]y_:+SHc
sFilePath = sPath; Z-PBCU
sFileName = sName; '~D4%WKT
this.nSplitter = nSpiltter; $0_K&_5w~
%Jt35j@Ee
nqj(V
} IzpE|8l
EZ)b E9
An. A1y
public String getSSiteURL() xE:jcA d$}
{ 1=R$ RI
return sSiteURL; 9zwD%3Ufn
} 4X+xh|R:U
TEz;:*,CG
n/_q
public void setSSiteURL(String value) I%YwG3uR
{ =!'9TS
sSiteURL = value; ~T_|?lU`R
} M\R+:O&
IVNH.g'
r%U6,7d=)
public String getSFilePath() {r_HcI(h
{ /ox7$|Jyr
return sFilePath; ;g0Q_F@;p
} $6rm;UH
W%L'nR~w$
wQ+pVu?6_
public void setSFilePath(String value) rl|'.~mc
{ ?^Rp" H
sFilePath = value; e )0 ]WJ
} & FhJ%JK
t1w5U+z
zZCl]cql
public String getSFileName() >+M[!;m}
{ 8^UF0>`'
return sFileName; jY=y<R_oK
} J&A1]T4d
b Hr^_ogN
wN[lC|1c
public void setSFileName(String value) dn 6]qW5
{ hxoajexU
sFileName = value; cq I $9
} 'nTlCYT
vi##E0,N'^
tWIOy6`
public int getNSplitter() w-K A~
{ *tqD:hiF
return nSplitter; [7I:Dm
} dA)T>
jFN0xGZ
+#Pb@^6"m
public void setNSplitter(int nCount) ##jJaSxG
{ k{qxsNM
nSplitter = nCount; <x}wy+SG
} !n-Sh<8
} KhR3$|fH<
;Nn(
v9f+ {Y%-
/* jEBn"]\D
**Utility.java oMbd1uus
*/ :s *
package NetFox; NY.Cr.}
IBa0O|*6
MLd;UHU
public class Utility { \IL)~5d
|4@cX<d.
VIF43/>(
public Utility() U"GxXrl
{ p<L7qwOii
B?j t?
/|v4]t-
} Y<T0yl?
</25J((
//线程睡眠 :E")Zw&sW3
public static void sleep(int nSecond) @aS)=|Ls\
{ 0F)v9EK(W4
try{ sC3Vj(d!i
Thread.sleep(nSecond); |=q~X}DA
} M(C">L]8
catch(Exception e) );!ND%
{ \TP$2i%W
e.printStackTrace (); 7i"b\{5
} /9_%NR[
} l#[Z$+!09
(HRj0,/^
//日志 n-9xfn0U~#
public static void log(String sMsg) XM\\Imw
{ >w.;A%|N
System.err.println(sMsg); (G|!{
} /r7xA}se^
?}Zo~]7E
# xO PF9
public static void log(int sMsg) R'gd/.[e
{ j@4MV^F2c
System.err.println(sMsg); _[[0rn$
} %IO*(5f
} 4Fp[94b
mu\1hKq;B
f-M:ap(O
/* $OZ= L
**TestMethod.java gAqK/9;
*/ 63E6nW M
package NetFox; BH'*I yv
~v8X>XDL?T
xL15uWk-
public class TestMethod { *O[/KR%
B?BOAH
,7wYa&
public TestMethod() xKu#OH
{ ///xx/weblogic60b2_win.exe znrO~OK
try{ {F<0e^*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6k hBT'n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qt L]x -O
SiteFileFetch fileFetch = new SiteFileFetch(bean); D&FDPaJM
fileFetch.start(); tdK&vqq
} |Ahf 01
catch(Exception e){e.printStackTrace ();} kN/YnY*J<
uGZGI;9f4
|3~m8v2-
} RG'iWA,9m`
C+'-TLeu
%Yu~56c-
public static void main(String[] args) "6d0j)YO
{ LAC&W;pJ"
new TestMethod(); !yv>e7g^
} cAN!5?D\
} =DdPwr 0Op
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