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)); 0z/h+,
} g;8M<`qvf
for(int i=0;i<nEndPos.length-1;i++) 1Yud~[c
{ cn$5:%IK
nEndPos = nStartPos[i+1]; ji}#MBac
} ASR-a't6
nEndPos[nEndPos.length-1] = nFileLength; +4Q[N;[+*
} ugno]5Ni
} pjACFVMFX
zt?h^zf}
0A.PD rM:
//启动子线程 2xDQ:=ec
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J==}QEhQ{
for(int i=0;i<nStartPos.length;i++) ?FN9rhAC
{ j~epbl)pC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0{Bf9cH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _74UdD{^o
nStartPos,nEndPos,i); m=H_?W;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vn'?3Eb<
fileSplitterFetch.start(); P@C c]Z
} `mrCu>7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |"Z-7@/k$i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D ZVXz|g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3)Zu[c[%'J
nEndPos = " + nFileLength); Vb2\/e:k
// fileSplitterFetch[nPos.length-1].start(); ZW>o5x__b
4Q;<Q"
Rs2-94$!5
//等待子线程结束 M+0x;53nz
//int count = 0; wazP,9W?
//是否结束while循环 Wm(:P
boolean breakWhile = false; 6+iK!&+=
n'yl)HA~>`
8)pB_en3sO
while(!bStop) L?HF'5o
{ `_GO=QQ
write_nPos(); ilv_D~|
Utility.sleep(500); >Fyu@u
breakWhile = true; vO]J]][
'*4iqPR;
MI\]IQU
for(int i=0;i<nStartPos.length;i++) )A"jVQjI%w
{ PK+ x6]x
if(!fileSplitterFetch.bDownOver) &U&Zo@ot"x
{ (xL :;
breakWhile = false; ailG./I+
break; +#~O'r]%GG
} j{)~QD?
} jB!W2~Z
if(breakWhile) ZOuR"9]
break; eQ<xp A
OF8WDo`
HyEa_9
//count++; "R23Pi
//if(count>4) i j/o;_
// siteStop(); _dr*`yXi
} 3za`>bUN
E67XPvo1+@
MKC$;>i
System.err.println("文件下载结束！"); 7/?DPwbx
} :G}DAUFN
catch(Exception e){e.printStackTrace ();} tq&Yek>C
} vL$|9|W(
IcFK,y%1
"y$ qrN-
//获得文件长度 ^wJEfac
public long getFileSize() )|RZa|`-G
{ p![&8i@ym
int nFileLength = -1; vU}: U)S
try{ $6!iBX@
URL url = new URL(siteInfoBean.getSSiteURL()); j=W@P-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C`0%C7
httpConnection.setRequestProperty("User-Agent","NetFox"); |{f~Ks%
P>wZ~Hjk
#h N.=~
int responseCode=httpConnection.getResponseCode(); 2:'lZQ
if(responseCode>=400) BC({ EE~R)
{ DWrbp
processErrorCode(responseCode); g/#~N~&
return -2; //-2 represent access is error YBvd q1
} ~KRnr0
q5p e~
E0YU[([G
String sHeader; eu9w|g
X`1p'JD
Q>=-ext}q
for(int i=1;;i++) *H"aOT^{
{ fK_~lGY(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;Iq5|rzDn
//Utility.log(in.readLine()); K_#UZA< Y
sHeader=httpConnection.getHeaderFieldKey(i); [))JX"a
if(sHeader!=null) _2OuskL
{ W2<3C
if(sHeader.equals("Content-Length")) K/|
{ .&iN(Bd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A"4@L*QV
break; #ZWl=z5aBi
} <KLg0L<W
} p=B?/Sqa
else y(v_-6b
break; ao$):,2*
} q- :4=vkn
} yW("G-Nm
catch(IOException e){e.printStackTrace ();} d}-'<Z#G
catch(Exception e){e.printStackTrace ();} `W"G!X-
j#3m|dQ
7Z0/(V.-
Utility.log(nFileLength); }g{_AiP rv
S+ebO/$>
b_vTGl1_6
return nFileLength; 3dG4pl~
} g1@wf
bSrZ{l
jNc<~{/
//保存下载信息（文件指针位置） GNU;jSh5
private void write_nPos() s;1e0n
{ sPCMckt
try{ |>2:eH
output = new DataOutputStream(new FileOutputStream(tmpFile)); CH;;V3
output.writeInt(nStartPos.length); _~A~+S}
for(int i=0;i<nStartPos.length;i++) DYRE1!
{ A1-qtAO]
// output.writeLong(nPos); _z8;lt
output.writeLong(fileSplitterFetch.nStartPos); 0d4cE10
output.writeLong(fileSplitterFetch.nEndPos); 85z;Zt0{
} Tpzw=bC^
output.close(); Rd%0\ B
} KlUqoJ;"
catch(IOException e){e.printStackTrace ();} 9j#@p
catch(Exception e){e.printStackTrace ();} 4j3oT)+8
} ?"j@;/=
9":2"<'+
#ElejQ|?
//读取保存的下载信息（文件指针位置） uD(t`W"
private void read_nPos() VAKy^nR5j
{ FkB{ SCJ
try{ 1;Xgc@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m r4b
int nCount = input.readInt(); +(mL~td01
nStartPos = new long[nCount]; dJl^ADX[@
nEndPos = new long[nCount]; ({M?Q>s
for(int i=0;i<nStartPos.length;i++) [H,u)8)
{ !8$RBD %
nStartPos = input.readLong(); YqU/\f+
nEndPos = input.readLong(); JJ5C}`(
} f1Zt?=
input.close(); kCA5|u
} cNj*E =~;
catch(IOException e){e.printStackTrace ();} wL2XNdo}<
catch(Exception e){e.printStackTrace ();} 'ere!:GJD
} 'msmXX@q
KzVTkDn,
2OalAY6RS
private void processErrorCode(int nErrorCode) J#7y< s
{ @!\K>G >9[
System.err.println("Error Code : " + nErrorCode); -0 0}if7
} GZ8:e3ri
I7mG/
%-j&e44
//停止文件下载 gj+3y9
public void siteStop() I/B1qw;MN
{ xK;e\^v
bStop = true; XP;x@I#l
for(int i=0;i<nStartPos.length;i++) ~>%DKJe
fileSplitterFetch.splitterStop(); Zq*eX\#C
3k'.(P|F
A1A3~9HuK
} aws"3O% uW
} .7Kk2Y
//负责部分文件的抓取 A}G|Yfn
**FileSplitterFetch.java E*|tOj9`1n
*/ Q)^g3J
package NetFox; .mPg0
x~/+RF XF
onl>54M^
import java.io.*; f0oek{
import java.net.*; ^\wl2
inF6M8 A1
A/ 0qk
public class FileSplitterFetch extends Thread { J_ J+cRwq
[xdj6W
\##`pa(8
String sURL; //File URL +v15[^F
long nStartPos; //File Snippet Start Position Q2\
long nEndPos; //File Snippet End Position $(q8y/,R*-
int nThreadID; //Thread's ID G;]:$J
boolean bDownOver = false; //Downing is over _N'75
boolean bStop = false; //Stop identical VzwPBQ -
FileAccessI fileAccessI = null; //File Access interface @2' %o<lF
(ZPXdr
jJ++h1 K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z$;"8XUM
{ F~_;o+e;X
this.sURL = sURL; ^?"^Pmw
this.nStartPos = nStart; zk=\lp2
this.nEndPos = nEnd; r4;Bu<PQN1
nThreadID = id; !T'X 'Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nq;#_Rkr
} 7Dt"]o"+
wUp)JI
P*G+eqX
public void run() r4eUZ .8R
{ *gu8-7'
while(nStartPos < nEndPos && !bStop) RJc%, ]:
{ X+ f9q0
i'tp1CI
SRz&Nb
try{ TzM=LvA
URL url = new URL(sURL); 77Q}=80GU;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (0jr;jv
httpConnection.setRequestProperty("User-Agent","NetFox"); #":a6%0Q
String sProperty = "bytes="+nStartPos+"-"; 7g6RiH}
httpConnection.setRequestProperty("RANGE",sProperty); 59!)j>f
Utility.log(sProperty); [7W(NeMk
\&q=@rJp(z
_CdROo6I
InputStream input = httpConnection.getInputStream(); {}\CL#~y
//logResponseHead(httpConnection); GLh]G(
b!a %YLL
^M Ey,
byte[] b = new byte[1024]; BaL]mIx
int nRead; T1NH eH>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v>-YuS
{ 1dv=xe.
nStartPos += fileAccessI.write(b,0,nRead); ')o0O9/;
//if(nThreadID == 1) 3Gd0E;3sk~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I@./${o
} >XE`h9
BGqa-d
CC8k&u,
Utility.log("Thread " + nThreadID + " is over!"); aRwnRii
bDownOver = true; {Y_Nj`#BT
//nPos = fileAccessI.write (b,0,nRead); (9GbG"
} ./w{L"E
catch(Exception e){e.printStackTrace ();} Hj~O49%j&
} 9<cOYY
} jXR16|
^ d\SPZ
/V^sJ($V$~
//打印回应的头信息 "ahvNx;x
public void logResponseHead(HttpURLConnection con) }kPVtSQ
{ ;CmOsA,1
for(int i=1;;i++) E`xU m9F
{ dlD}Ub
String header=con.getHeaderFieldKey(i); :p-Y7CSSu
if(header!=null) iJP{|-h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z"tQpJg
Utility.log(header+" : "+con.getHeaderField(header)); qrDcL>Hrn
else T[2}p=<%
break; 3j*'HST
} 3{3/: 7
} `clB43i
.~`Y)PON
!F7:i
public void splitterStop() )N)ljA3]
{ rYGRz#:~+
bStop = true; hKksVi
} 4vqNule
C1QWU5c v
j>!sN`dBj
} Kbas-</Si
\"d?=uFe
?}sOG?{
/* o#e7,O
**FileAccess.java j'Wp
*//文件访问(定位，写) &;v!oe
package NetFox; ;BI)n]L
import java.io.*; YzV(nEW
K0<yvew
x!?Z*v@I
public class FileAccessI implements Serializable{ M 9"-WIG@h
2Xgx*'t\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NG9vml
RandomAccessFile oSavedFile; d@g2k> >
long nPos; 0w3b~RJ
0&$xX!]
Gvn: c/m;
public FileAccessI() throws IOException =|0/Ynfe
{ l0`'5>
this("",0); dS$ji#+d$
} QymD-A"P
O71BM@2<
%fpsc_
public FileAccessI(String sName,long nPos) throws IOException \!wh[qEQ\
{ `Bu9Nq
oSavedFile = new RandomAccessFile(sName,"rw"); EcW1;wH
this.nPos = nPos; *V|zx#RN
oSavedFile.seek(nPos); p7UTqKi
} @L;C_GEa
XS|mKuMcC
v3^t/[e~:
public synchronized int write(byte[] b,int nStart,int nLen) H[BYE
{ C*G/_`?9
int n = -1; MPvWCPB
try{ qGa<@ b
oSavedFile.write(b,nStart,nLen); KjYDFrR4
n = nLen; ,?y7,nb
} HRHrSf7
catch(IOException e) D rTM$)
{ c[{UI
e.printStackTrace (); a: IwA9!L
} ,n5a])Dg
gj;@?o0
wOcg4HlW
return n; )E`+BH
} oKiD8':
q?iCc c
!4B_$6US
} o2}N=|&
xBWx+My
i+AUQ0Zbf6
/* [q$e6JwAt
**SiteInfoBean.java pqq?*\W&[v
*/ \HG$V>2
package NetFox; s##Ay{
]ymC3LV]
.K7C-Xn=
public class SiteInfoBean { 6Ahr_{
7TdQRB
6 [ _fD
private String sSiteURL; //Site's URL Ilef+V^qr
private String sFilePath; //Saved File's Path p`p?li
private String sFileName; //Saved File's Name k<Oy%+C
private int nSplitter; //Count of Splited Downloading File %M6 c0d[9-
C8MWIX}
jGiw96,Y
public SiteInfoBean() 4:`[qE3
{//nSplitter的缺省值为5 raHVkE{<
//default value of nSplitter is 5 2Oi'E
this("","","",5); m&cvU>lC
} >Bx8IO1_\d
5Hy3\_ +
>[P%Ty);
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l/F!Bq[*g
{ -lnevrl
sSiteURL= sURL; +"Ub/[J{G1
sFilePath = sPath; 0BDoBR
sFileName = sName; cz>mhD
this.nSplitter = nSpiltter; J{!'f| J
|hD~6a
cIZ[[(Db
} ]b)!YPo
DO%Pwfkd
, QA9k$`
public String getSSiteURL() ifHU|0_=
{ sW'6}^Q
return sSiteURL; )-#i8?y3C
} `:gYXeR
yU!GS-
{\Ys@FF
public void setSSiteURL(String value) @E(P9zQ/zy
{ V" }*"P-%
sSiteURL = value; %r P !
} WP!il(Gr
x97H(*
wo]ks}9
public String getSFilePath() oX*b<d{\N
{ Y2D>tpqNw
return sFilePath; [%?hCc
} sL8>GtVo
GVZTDrC
"?[7#d])
public void setSFilePath(String value) -U:2H7
{ {s9<ej~<R
sFilePath = value; \H[Yyp4
} d QDLI
>qn+iI2U
RY9.n
public String getSFileName() Z:TFOnJ
{ S[^nSF
return sFileName; fOLnK y#
} W W35&mI)k
F#KF6)P
[brkx3h
public void setSFileName(String value) UT~4Cfb
{ `xGT_0&ck
sFileName = value; @Rf^P(
} tbS#^Y
_E(x2BS?
tStJ2-5*t
public int getNSplitter() V4Qz*z%
{ DEcGFRgN~
return nSplitter; ILNXaJ'0a
} 5E0wn'
)Z&HuEg{ZR
_C5nApb
public void setNSplitter(int nCount) e]Puv)S>{8
{ x?gQ\0S<
nSplitter = nCount; m'c#uU
} d#4Wj0x
} L@+Z)# V
eq{ [?/
)u-ns5
/* py=i!vb&Z%
**Utility.java xmOM<0T
*/ 1j+eD:d'
package NetFox; \:h0w;34O
4NJVW+:2
88#N~j~P
public class Utility { OFp#<o,p
$8=(I2&TW
my]P_mE
public Utility() hj+p`e S
{ :Fc8S9
N7a[B>+`
51z/
} 3#B@83C0Z
fH; |Rm
//线程睡眠 t={poQC~
public static void sleep(int nSecond) +<z7ds{Z
{ $Q=$?>4U
try{ :ET x*c
Thread.sleep(nSecond); 8pd&3G+
} k~& o
catch(Exception e) *XHj)DC;
{ L-j/R1fTvl
e.printStackTrace (); G%Y*q(VrEu
} \_?yzgf
} pTN%;`) {
xS-w\vbLV
//日志 b#e]1Q
public static void log(String sMsg) @PKAz&0
{ \6U 2-m'
System.err.println(sMsg); UC.8DaIPN
} DhHtz.6
N-Qu/,~+
x4@MO|C
public static void log(int sMsg) 6<#Slw[
{ Oxpo6G
System.err.println(sMsg); 58 kv#;j
} 2lF WW(
} A(PE
n&(3o6i'
0=2H9v
/* IcRM4Ib))Q
**TestMethod.java 87R%ke
*/ cl?< 7
package NetFox; =7#u+*Yr9
W31LNysH!;
BEFe~* ~
public class TestMethod { PE^eP}O1
uQO(?nCi
/@6E3lhS
public TestMethod() P>>f{3e.
{ ///xx/weblogic60b2_win.exe y|$vtD%c
try{ m9 ^m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SlR7h$r'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?56~yQF/2
SiteFileFetch fileFetch = new SiteFileFetch(bean); |C^ c0
fileFetch.start(); tWcizj;?wK
} ^ sS>Mts
catch(Exception e){e.printStackTrace ();} w{RNv%hJ$=
r4;^c}
"0!~g/X`rK
} dBsRm{aS
*sjj"^'=
HI}pX{.\
public static void main(String[] args) Z3OZPxm
{ ,xm;JXJ
new TestMethod(); )-MA!\=<
} }_Tt1iai*
} IvY,9D
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