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)); BSm"]!D8*
} 2k.VTGak
for(int i=0;i<nEndPos.length-1;i++) X*2W4udF
{ rB[J*5v
nEndPos = nStartPos[i+1]; !Z$d<~Mq q
} JEto_&8,C
nEndPos[nEndPos.length-1] = nFileLength; N~)-\T:ap
} QH'*MY
} :&BPKqKp
@c|=onx5
2) X#&IE
//启动子线程 .6wPpLG?{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1:-'euA"
for(int i=0;i<nStartPos.length;i++) yv,FzF}7
{ \=%lH=yS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ta?J;&<u]/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (?4%Xtul1
nStartPos,nEndPos,i); 2 @#yQB1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tguB@,O
fileSplitterFetch.start(); 5JzvT JMx
} n>'(d*[e&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eRMN=qP.q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^j}C]cq{Xg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F-m%d@P&X
nEndPos = " + nFileLength); :kgh~mx5LF
// fileSplitterFetch[nPos.length-1].start(); F6\{gQ<E
d( v"{N}
Df6i*Ko|
//等待子线程结束 #h;
//int count = 0; k|;a"56F
//是否结束while循环 {)" 3
boolean breakWhile = false; (|QJ[@?q
!Tnjha*
0Ui.nz j
while(!bStop) $TUYxf0q
{ u&zY>'}zm
write_nPos(); 5 ^{~xOM5
Utility.sleep(500); *Soi
breakWhile = true; R$&;
5Kzt8Tv[
{ZeY:\G~
for(int i=0;i<nStartPos.length;i++) u zZ|0
{ U^PXpNQ'
if(!fileSplitterFetch.bDownOver) 3%POTAw%
{ <F9-$_m
breakWhile = false; x{R440"
break; "| nXR8t.r
} j yHa}OT
} S!?T0c?>
if(breakWhile) :;%Jm
break; BE?]P?r?
pCKP{c=6Q
-E7mt`:d
//count++; _pdKcE\X
//if(count>4) YSnh2 Bq
// siteStop(); J9T2 p\5
} 7@c!4hmrU
+#IUn
$LXa]
System.err.println("文件下载结束！"); B}"R@;N
} i%i~qTN
catch(Exception e){e.printStackTrace ();} opa/+V3E4
} #cY[c1cNv
LLx0X O@
Ca |}i+
//获得文件长度 *V&M5
public long getFileSize() :2/L1A)O
{ NM. e4
int nFileLength = -1; o0r&w;!
try{ B!'K20"gF
URL url = new URL(siteInfoBean.getSSiteURL()); VEWW[T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4%0s p
httpConnection.setRequestProperty("User-Agent","NetFox"); hW*o;o7u
kQ+y9@=/g
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int responseCode=httpConnection.getResponseCode(); w{tA{{
if(responseCode>=400) A{_CU-,
{ v47' dC
processErrorCode(responseCode); J jAxNviG
return -2; //-2 represent access is error WuK<?1meN
} V!:!c]8F
e:G~P u`
ai 4k?
String sHeader; eT%x(P
{a[BhK'g
I_1?J* b4k
for(int i=1;;i++) Y}[<KK}_
{ hb3n- rO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k+_>`Gre}
//Utility.log(in.readLine()); O*N:A[eW
sHeader=httpConnection.getHeaderFieldKey(i); ? 2}%Rb39
if(sHeader!=null) n@pwOHQn<|
{ ed'[_T}T3t
if(sHeader.equals("Content-Length")) c]pz&
{ "~Fg-{jM%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); INndTF
break; #Y= A#Yz,{
} 67EGkW?hbt
} >nkVZ;tL
else FG${w.e<
break; qGX@mo({
} h3F559bw/<
} $:s@nKgnD~
catch(IOException e){e.printStackTrace ();} 5AT^puL]]
catch(Exception e){e.printStackTrace ();} s9C^Cy^su
0H_Ai=G
(aYu[ML
Utility.log(nFileLength); ?e9tnk3
21!X[)r
Y1cL dQn
return nFileLength; $#V'm{Hh
} z$&B7?
|5flvkid
>33=0<
//保存下载信息（文件指针位置） Y%i<~"k
private void write_nPos() 56C8)?
{ mAlG}<
try{ K+Him] b
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dbn~~P
output.writeInt(nStartPos.length); e"866vc,
for(int i=0;i<nStartPos.length;i++) 1(;{w+nM
{ aQoB1qd8
// output.writeLong(nPos); Q7x[08TI
output.writeLong(fileSplitterFetch.nStartPos); {/noYB<;
output.writeLong(fileSplitterFetch.nEndPos); fDr$Wcd~
} '6zZ`Ll9
output.close(); hT^&*}G
} @>2]zMFf
catch(IOException e){e.printStackTrace ();} :s_o'8z7L
catch(Exception e){e.printStackTrace ();} "e-z2G@z
} knO X5UnS
gb,ZN^3<-
];5J
//读取保存的下载信息（文件指针位置） mX|M]^_,z
private void read_nPos() P 0\`4Cr!
{ +kWWx#L#
try{ EUSM4djL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "nr?WcA
int nCount = input.readInt(); xn, u$@F
nStartPos = new long[nCount]; <?A4/18K
nEndPos = new long[nCount]; 7fqQ
for(int i=0;i<nStartPos.length;i++) <^nS%hXEr
{ Q7y'0s
nStartPos = input.readLong(); w!UF^~
nEndPos = input.readLong(); KY&Lv^1_|
} |}{gE=]
input.close(); ^m7y=CJM
} 4lPO*:/
catch(IOException e){e.printStackTrace ();} QP~["%}T
catch(Exception e){e.printStackTrace ();} bEF2-FO
} Fepsa;\sU
W9l](Ow
;tQc{8O6L
private void processErrorCode(int nErrorCode) pYcs4f!?p
{ #j7&2L
System.err.println("Error Code : " + nErrorCode); Zf>:h
} [%^0L~:
QE/kR!r
";dS~(~
//停止文件下载 \asn^V@"zz
public void siteStop() XR]bd
{ ;):;H?WS|A
bStop = true; `Ku:%~$/
for(int i=0;i<nStartPos.length;i++) <e! TF@
fileSplitterFetch.splitterStop(); KxErWP%
>}wFePl
9O &]!ga
} p7AsNqEp
} KsGW@Ho:
//负责部分文件的抓取 ZeG4z({af
**FileSplitterFetch.java BoT#b^l
*/ @@@}FV&
package NetFox; PM!JjMeQh
(J4( Ge
Dlz0*eHD
import java.io.*; v,opyTwG|
import java.net.*; $<nD-4p
Tf=1p1!3
ku/vV+&O
public class FileSplitterFetch extends Thread { mm_)=Ipj>
*_YH}U
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String sURL; //File URL oM1C/=8
long nStartPos; //File Snippet Start Position .0,G4k/yv
long nEndPos; //File Snippet End Position a{ke%W$*P
int nThreadID; //Thread's ID &W3srJo
boolean bDownOver = false; //Downing is over ADF<5#I
boolean bStop = false; //Stop identical Wlg1t~1=
FileAccessI fileAccessI = null; //File Access interface zvGncjMkC
5222"yn"c
7 2i&-`&4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1 jLQij
{ L_T+KaQCH
this.sURL = sURL; |;:Kn*0/]
this.nStartPos = nStart; :CqR1_n%
this.nEndPos = nEnd; "%Ief4
nThreadID = id; w15a~\Qu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #"oLz"{
} i<$?rB!i<1
3w>1R>7
t"9r`0>
public void run() +9]t]Vrw
{ s/t,6-~EH
while(nStartPos < nEndPos && !bStop) zk1]?
{ ZUj1vf6I
kbvF 9#
-+i7T^@|
try{ -p0*R<t
URL url = new URL(sURL); oR%cG"y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HoX={^aG%
httpConnection.setRequestProperty("User-Agent","NetFox"); S -,$ (
String sProperty = "bytes="+nStartPos+"-"; djoP`r
httpConnection.setRequestProperty("RANGE",sProperty); 'w1ll9O
Utility.log(sProperty); 'k}w|gNB
A|PZ<WAY
%qqCpg4
InputStream input = httpConnection.getInputStream(); ts@w9|
//logResponseHead(httpConnection); V:t{mu5j
8LF=l1=~
%x;~o:
byte[] b = new byte[1024]; [OPF3W3z
int nRead; -1hCi!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _J2?B?S/j
{ Jj0:p"
nStartPos += fileAccessI.write(b,0,nRead); \d.\M
//if(nThreadID == 1) 3QXsr<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @:Ft+*2
} A:4&XRYZY
C \5yo
nxEC6Vh'
Utility.log("Thread " + nThreadID + " is over!"); b%x=7SMXO
bDownOver = true; d%L/[.&
//nPos = fileAccessI.write (b,0,nRead); 2zbn8tO
} J!|R1
catch(Exception e){e.printStackTrace ();} L)<~0GcP
} M%$ITE
} h'GOO(
uwi.Sg11
4Q1R:Ra
//打印回应的头信息 ,ExY.'%1
public void logResponseHead(HttpURLConnection con) ,*9gy$
{ Jq"3xj
for(int i=1;;i++) YADXXQ"
{ xEq?[M
String header=con.getHeaderFieldKey(i); O`!XW8
if(header!=null) ml)\RL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #N|JC d_
Utility.log(header+" : "+con.getHeaderField(header)); ,y-!h@(
else ? 47"$=G
break; ' Qlj"U
} f6\4,()
} (+xT5 2
mBB"e"o
;*+H&
public void splitterStop() !M)] 1Y
{ `WMU'ezF
bStop = true; Z;tWV%F5
} ~$//4kES
S|KUh|=Q
{md5G$*%
} ~PAI0+*"q
'~7zeZ'
K:VZ#U(_
/* B>S>t5$
**FileAccess.java CQmozh-
*//文件访问(定位，写) ^U*1_|Jh
package NetFox; (7&b)"y
import java.io.*; xh#pw2v7V
B\aVE|~PB
P;K3T![
public class FileAccessI implements Serializable{ ={]POL\ A
~e)"!r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y]`o-dV
RandomAccessFile oSavedFile; tnBCO%uG
long nPos; Yne1MBK
~gQYgv<7
VV54$a
public FileAccessI() throws IOException 9pr.`w
{ f;OB"p
this("",0); /<-=1XJI
} zK_P3rLsS
,_<|e\>~
X(.[rC>
public FileAccessI(String sName,long nPos) throws IOException .r-Zz3
{ "j_cI-@6
oSavedFile = new RandomAccessFile(sName,"rw"); 6kAGOjO
this.nPos = nPos; @w(|d<5l:L
oSavedFile.seek(nPos); 1*6xFn
} 9&6P,ts%Q
wZJbI[r
W4P+?c>'2
public synchronized int write(byte[] b,int nStart,int nLen) $Xu/P5
{ J,=ZUh@M
int n = -1; 1U^KN~!
try{ eJ ^I+?h
oSavedFile.write(b,nStart,nLen); Ejf5M\o
n = nLen; LylCr{s7
} Xx2t0AIB
catch(IOException e) !)`*e>]x
{ yc`3)
e.printStackTrace (); (c"!&&S^ =
} ox\D04:M
R>&8%%#
\L}7.fkb8
return n; l,3,$
} R[*n3 wB
5}! 36SO\
r1}1lJ>7H
} h qhX
Eht8~"fj
][#|5UK8L
/* .RAyi>\e
**SiteInfoBean.java H;q[$EUNb
*/ 6hcK%0z
package NetFox; @o#Yq n3Y
Nz*,m'-1e
rQ2TPX<?a
public class SiteInfoBean { !mB `FC
C?W}/r[
1{a4zGE?[
private String sSiteURL; //Site's URL p8?"}
private String sFilePath; //Saved File's Path nqTOAL9FF
private String sFileName; //Saved File's Name z[O*f#t
private int nSplitter; //Count of Splited Downloading File vCK+v r!
KDV.ZSF7
a0PU&o1EF
public SiteInfoBean() \[)SK`cwd
{//nSplitter的缺省值为5 VeY&pPQ
//default value of nSplitter is 5 l]Ym)QP
this("","","",5); 5j0 Ib>\
} Fq oh!F
Gxxz4
|YV> #l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e"{"g[b/7
{ {^:NII]
sSiteURL= sURL; EQw7(r|v:
sFilePath = sPath; u86@zlzd
sFileName = sName; 28c6~*Te#
this.nSplitter = nSpiltter; e{XzUY6
% -+7=x
3)2{c
} wf\7sz
.Y8P6_
cq3Z}Cp
public String getSSiteURL() lkR^2P
{ bGy|T*@
return sSiteURL; {X_I>)Wg
} qHo Hh
z}7}D!
hn/yX|4c(
public void setSSiteURL(String value) &@BAVc z
{ Ai^0{kF6
sSiteURL = value; JL{fW>5y|
} J~oxqw}
WiQVZ{
o1*P|.`
public String getSFilePath() 3p?nQ O)L
{ C+%eT&OO
return sFilePath; [?qzMFb
} }QQ 7jE
`R7dn/
X?&{< vz
public void setSFilePath(String value) _6`GHx
{ MA}}w&
sFilePath = value; X%N!gy
} PBFpV8P,
s1#A0%gx
bKzG5|Qu
public String getSFileName() ![fNlG!r
{ #Ak|p#7 ^
return sFileName; 1wdc4>
} ~Eb:AC5
v<<ATs%w
:*DWL!a
public void setSFileName(String value) FZZO-,xa
{ ~3Zz.!F
sFileName = value; nD]MgT
} ("}C& 6)cB
9k6/D.Dz
;cPPx`0$9
public int getNSplitter() Y|J=72!]
{ YK$[)x\S
return nSplitter; iVf7;M8O
} ~{-Ka>A
])%UZM6
h|`R[
public void setNSplitter(int nCount) 0E,QOF{o
{ =PNkzFUo
nSplitter = nCount; l?V#;
} A"s?;hv\fS
} j{2 0
B.;@i;7L
3^-R_
/* ~gOZ\jm}
**Utility.java HY?#r]Ryt
*/ oOAkwc%)b
package NetFox; v0=v1G*rvJ
c#1kg@q@
~RwoktO
public class Utility { suW|hh1/Ya
)C{20_
;*9<lUvu
public Utility() >j$aY
{ i_*.
*PB/I4>{
Ex|Z@~T12
} 1^V.L+0s]
@Bjp7v:w
//线程睡眠 kdx06'4o
public static void sleep(int nSecond) DHuvHK0#
{ 5} ur,0{
try{ <sM_zoprc
Thread.sleep(nSecond); @]8flb )T
} BA@M>j6d
catch(Exception e) *:"60fkoU
{ MLM/!N 7
e.printStackTrace (); $>uUn3hSx\
} 4K dYiuz0`
} >,'guaa
=h +SZXe<r
//日志 }Qe(6'l_
public static void log(String sMsg) A:2CP&*
{ XqhrQU|wM
System.err.println(sMsg); W/WP }QM
} e6tU8`z
(: kn)
Iw)m9h
public static void log(int sMsg) #R31VQwK5
{ :%j"l7=>
System.err.println(sMsg); )Y'g;
} ZNk[Jn [.
} {hN<Ot
!7Qj8YmS
I|K!hQ"m
/* :oC;.u<*8
**TestMethod.java P?c V d2Y
*/ {D(l#;,iX2
package NetFox; FwHqID_!:l
"lC>_A
j)@{_tv6;
public class TestMethod { ;;XY&J
9^N(s7s
s|c}9/Xe)
public TestMethod() OpU9:^r
{ ///xx/weblogic60b2_win.exe s'l|Ii
try{ \w1',"l`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?OoI63&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aaN/HE_
SiteFileFetch fileFetch = new SiteFileFetch(bean); .3n\~Sn
fileFetch.start(); ydY 7 :D
} $UK m[:7
catch(Exception e){e.printStackTrace ();} ?$tD
L]"$dF
b\o>4T
} 3XQe? 2:<
5 $$Cav
X%JyC_~<
public static void main(String[] args) ].aFdy
{ 0kls/^0,
new TestMethod(); }lhk;#r
} yD.(j*bMK;
} Rbr:Q]zGN
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