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)); xXb7/.*qE
} s Zn@ye^
for(int i=0;i<nEndPos.length-1;i++) #/N;ScyUJT
{ wFbw3>'a9
nEndPos = nStartPos[i+1]; B:mtl?69g
} &#/UWv}f 0
nEndPos[nEndPos.length-1] = nFileLength; ^*?mb)
} uwI$t[
} ,:[\h\5m
9}-;OJe
OQnb^fabY
//启动子线程 &VPfI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bi{G :xt
for(int i=0;i<nStartPos.length;i++) 'kuLkM,
{ LI}@qLe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P~}Yj@2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8kdJ;%^N
nStartPos,nEndPos,i); E+Eug{+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +HDfEo T
fileSplitterFetch.start(); DpbprT7_
} z:1"d R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R1cOUV,y[/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $y$E1A6h+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }1kZF{KD<[
nEndPos = " + nFileLength); ;$.^
// fileSplitterFetch[nPos.length-1].start(); Sdzl[K/}
Kcu*Z
MA1y@
//等待子线程结束 j{$2.W$
//int count = 0; GI5#{-)
//是否结束while循环 V}aZ}m{J
boolean breakWhile = false; n@=D,'cn
Zjkg"
\yhj{QS.k
while(!bStop) @1vpkB~ w
{ )z\ 73|w
write_nPos(); cj;k{Moc
Utility.sleep(500); ^ *1hz<
breakWhile = true; bHRRgR`,
[QDM_n
mS?W+jy%
for(int i=0;i<nStartPos.length;i++) _aP2gH
{ cI\&&<>SlG
if(!fileSplitterFetch.bDownOver) 2cQG2N2*
{ fB=j51Lw
breakWhile = false; frRO?
break; v"YaMbu
} D KRF#*[=d
} /l` "@
if(breakWhile) nV/;yl4e{
break; sl_f+h0
yvCX is
h$)4%Fy
//count++; "Z]z9(
//if(count>4) LV8{c!"
// siteStop(); P$v9
} Ex+E66bE
2l}H=DZV
\C kb:
System.err.println("文件下载结束！"); #BW:*$>}
} B=)tq.Q7
catch(Exception e){e.printStackTrace ();} tjJi|
} , Y^GQ`~#
)v+\1
CwaW>(`v
//获得文件长度 'M35L30
public long getFileSize() M*Ri1
{ m](q,65 2
int nFileLength = -1; (mgv:<c;BA
try{ ZC97Z sE
URL url = new URL(siteInfoBean.getSSiteURL()); KkZS6rD\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Izdj*HL;A
httpConnection.setRequestProperty("User-Agent","NetFox"); %?PRBE'}'
~j yl
5Ve T8/7Q
int responseCode=httpConnection.getResponseCode(); -eFq^KP2
if(responseCode>=400) 8Z>=sUMQ
{ \t ^9UN
processErrorCode(responseCode); ,HwOMoP7
return -2; //-2 represent access is error BM[jF=0
} qS[KB\RN1
j>)yV@g/
J3y4D}
String sHeader; s >7(S%#N
|W*i'E
T7Qw1k
for(int i=1;;i++) zRFvWOxC\
{ )#v0.pE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O0QK `F/)*
//Utility.log(in.readLine()); MNocXK
sHeader=httpConnection.getHeaderFieldKey(i); .9!?vz]1
if(sHeader!=null) k? !'OHmBL
{ \*\)zj*r
if(sHeader.equals("Content-Length")) QygbfW6u
{ PDhoCAh !
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HG&rE3@
break; lx&;?QQ
} wqAj=1M\
} c;7`]}fGu
else VH6J @m
break; h`pXUnEZ
} &5Huv?^a'
} 5^C.}/#>F
catch(IOException e){e.printStackTrace ();} .NT9dX
catch(Exception e){e.printStackTrace ();} F~x>\?iN
z<,-:=BC"
c63yJqiW
Utility.log(nFileLength); 2Z7r ZjXW
DgKe!w$
m[D]4h9
return nFileLength; tQIa6c4|
} lR0WDJv
NH;.!xq:
DGO\&^GT^
//保存下载信息（文件指针位置） fl o9iifZ
private void write_nPos() O9R[F
{ 9;tY'32/
try{ ;0-Y),
output = new DataOutputStream(new FileOutputStream(tmpFile)); e<r}{=1w
output.writeInt(nStartPos.length); T[eb<
for(int i=0;i<nStartPos.length;i++) !EB[Lutm
{ #9(L/)^
// output.writeLong(nPos); 3pjK`"Nmz\
output.writeLong(fileSplitterFetch.nStartPos); %SJFuw"
output.writeLong(fileSplitterFetch.nEndPos); 1Y{pf]5Wx
} abkt&981K+
output.close(); yR[htD`
} d'2q~
catch(IOException e){e.printStackTrace ();} I3d!!L2ma
catch(Exception e){e.printStackTrace ();} _ cm^Fi5
} `R,g_{Mj
Og<nnq
!b8.XGo
//读取保存的下载信息（文件指针位置） Q[MWzsx
private void read_nPos() :bu]gj4e
{ ><H*T{ Pg
try{ M&^Iun
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1XJLGMW,
int nCount = input.readInt(); pvYBhTz0
nStartPos = new long[nCount]; 67A g.f6-
nEndPos = new long[nCount]; `,$PRN"]
for(int i=0;i<nStartPos.length;i++) }$Z0v`
{ y-lBaTE9
nStartPos = input.readLong(); dQJ)0!B
nEndPos = input.readLong(); =>X"
} i^hEL2S/A
input.close(); ")D5ulb\
} UQ}#=[)2e
catch(IOException e){e.printStackTrace ();} 89\DS!\x9
catch(Exception e){e.printStackTrace ();} 'oS= d
} $M|
?C(3TKH
;-6
private void processErrorCode(int nErrorCode) kn&>4/')
{ T1i}D"H %
System.err.println("Error Code : " + nErrorCode); oyq9XW~ D
} I8Q!`KJ
oe,yCdPs
Xhp={p;
//停止文件下载 ^~7ouA
public void siteStop() 9z kRwrQ
{ ]4eIhj?
bStop = true; Eh&-b6:
for(int i=0;i<nStartPos.length;i++) ~zhP[qA})
fileSplitterFetch.splitterStop(); 5aJd:36I
% 9} ?*U
AI#.G7'O
} "I0F"nQ
} FgnPh%[u
//负责部分文件的抓取 tO+Lf2Ni+
**FileSplitterFetch.java ].HHTCD`c
*/ D8f4X w}=
package NetFox; si#1sdR
raJv$P
SSysOeD+
import java.io.*; U o[\1)
import java.net.*; ZK5 wZU
#D-Ttla
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public class FileSplitterFetch extends Thread { /q5!p0fH*
;}}k*< Z
'q\[aKEX=
String sURL; //File URL J=6( 4>
long nStartPos; //File Snippet Start Position KZGy&u >`
long nEndPos; //File Snippet End Position rmJ`^6V
int nThreadID; //Thread's ID NM+(ss'
boolean bDownOver = false; //Downing is over Sy"!Q%+|
boolean bStop = false; //Stop identical c0QKx=
FileAccessI fileAccessI = null; //File Access interface 9wdl1QS
A.cNOous|
Td5yRN! ?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $[V-M\q
{ PnZY%+[I
this.sURL = sURL; #AF.1;(k
this.nStartPos = nStart; _&e$?hY
this.nEndPos = nEnd; 7'.]fs:
nThreadID = id; ^NXxMC(e+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]h%~'8g,
} *AJYSa,z
B3&C=*y
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public void run() )4^Sz&\
{ S`pBEM
while(nStartPos < nEndPos && !bStop) `y$@zT?j
{ szGGw
eXi}-~o
4(&sw<k
try{ w5;d/r<q
URL url = new URL(sURL); p|Qn?^C:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?H!QV;ku
httpConnection.setRequestProperty("User-Agent","NetFox"); Igh=Z %
String sProperty = "bytes="+nStartPos+"-"; Y3O/`-9i
httpConnection.setRequestProperty("RANGE",sProperty); 3|PV.
Utility.log(sProperty); _*++xF1
th%T(D5n
yq12"Rs
InputStream input = httpConnection.getInputStream(); #Wq@j1?
//logResponseHead(httpConnection); ''H;/&nDX
t5k=ngA
p4vX3?&1W
byte[] b = new byte[1024]; <Yn-sH
int nRead; =F09@C,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }#2I/dn
{ J+m1d\lBu
nStartPos += fileAccessI.write(b,0,nRead); b}!T!IP}
//if(nThreadID == 1) PO*0jO;%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \.YJs"<3
} oAgU rl;R
I ;F\'P)e
.*&F
Utility.log("Thread " + nThreadID + " is over!"); &M7AM"9
bDownOver = true; v9"03=h
//nPos = fileAccessI.write (b,0,nRead); +LF`ZXe8l
} (BGflb
catch(Exception e){e.printStackTrace ();} SW7AG;c=
} 3;F up4!4}
} ` >[Offhd
cUr5x8<W).
_ ($U\FW
//打印回应的头信息 7{p6&xXx
public void logResponseHead(HttpURLConnection con) ~p x2kHZ
{ v;(k7
for(int i=1;;i++) Bhk@0\a
{ <OTx79m
String header=con.getHeaderFieldKey(i); O?0`QMY
if(header!=null) q +!i6!6r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gwDVWhq
Utility.log(header+" : "+con.getHeaderField(header)); jD?*sd
else dH)\zCt
break; IHv>V9yiG
} t:YMF$Z
} KM/c^a4V
Pr3>}4M
OlM3G^1e1
public void splitterStop() yM*_"z!L
{ _8e0vi!~2
bStop = true; GYtp%<<9;
} ]QJ7q}
l:*.0Tj
{J-Ojw|Y b
} >dnDN3x
Q+*@!s
/L=Y8tDt
/* 7MIrrhk
**FileAccess.java wZt2%+$6m
*//文件访问(定位，写) MH=Ld=i
package NetFox; >aT~G!y
import java.io.*; u5tUm
M/kBAxNIC|
5ljEh -
public class FileAccessI implements Serializable{ Esf\Bo"
aX? tnDv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P>'29$1'
RandomAccessFile oSavedFile; Lc0=5]D
long nPos; 6Oy6r
4jW <*jM
{/i&o
public FileAccessI() throws IOException ;_m;:<
{ mpD[k9`x#
this("",0); lS?#(}a1)
} [0lO0ik>G
.:=5|0m
!UHX?<3r
public FileAccessI(String sName,long nPos) throws IOException \{={{O
{ fa!8+kfi
oSavedFile = new RandomAccessFile(sName,"rw"); >^D5D%"
this.nPos = nPos; FY pspv?4
oSavedFile.seek(nPos); V^_U=Ed@M
} #lF 2qw
WTu!/J<\
dte-2?%~j
public synchronized int write(byte[] b,int nStart,int nLen) 8d(l)[GZt
{ oo|Nu+
int n = -1; K+`deH_d
try{ } wx(P3BHD
oSavedFile.write(b,nStart,nLen); I2z6iT4nB
n = nLen; $?uLFD
} oG c9 6B%
catch(IOException e) "Rn@yZV
{ UQjYWXvi
e.printStackTrace (); pW_mS|
} *A0*.>@N
`E|>K\
nI/kX^Pd
return n; L$ZsNs+
} 9[h8Dy
N'Vj& DWC
1z_1Hl
} e^UUR-K%
9r ](/"=f
W Haf}.V
/* Qjmo{'d
**SiteInfoBean.java Qe`Nb4xf
*/ b^"mQ
package NetFox; TWdhl9Ot
Tn?D~?a*O
Z9i~>k
public class SiteInfoBean { e^v\K[
cCcJOhk|d
j9.%(*
private String sSiteURL; //Site's URL iYGa4@/uM
private String sFilePath; //Saved File's Path r|y\FL
private String sFileName; //Saved File's Name n<ecVFft
private int nSplitter; //Count of Splited Downloading File E5\>mf ,;u
L;fz7?_j
B.~[m}
public SiteInfoBean() rdH^"(
{//nSplitter的缺省值为5 ?(M]'ia{
//default value of nSplitter is 5 G> sqfYkK
this("","","",5); O6ltGtF
} sn+ kFvk}S
+ZkJ{r0,(
IiV]lxiE]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QT4vjz+|
{ 6t gq.XL^n
sSiteURL= sURL; a!.Y@o5Ku
sFilePath = sPath; /*Gbl
sFileName = sName; z6fY_LL
this.nSplitter = nSpiltter; yF-`f _
3dgPP@7d$
KON^
} Rb0{W]opt+
a..LbQQ
KBA&s
public String getSSiteURL() Z>*a:|
{ 8v6AfTo%
return sSiteURL; Q1!+wC
} {ITxHt
f]2;s#cu
|#Q0UM|'Q
public void setSSiteURL(String value) EmyE%$*T
{ 1w+)ne_&
sSiteURL = value; gFXz:!A
} 31N5dIi,
[Bj\h7G
w8F`RRHEE
public String getSFilePath() 'fZ\uMdTx
{ hJ?PV@xy
return sFilePath; ^~s!*T)\
} H-eHX3c7
)U{\c2b
hLT?aQLx
public void setSFilePath(String value) eL [.;_
{ $)6x3&]P
sFilePath = value; 7_J0[C!G
} }/jWa|)f
mNJCV8 <
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public String getSFileName() 0JW =RW
{ u.}H)wt
return sFileName; <(1[n pS&+
} (Mw+SM3<
!1l~'/r
I(b]V!mj:
public void setSFileName(String value) NzS`s,N4/0
{ ]$U A5/a
sFileName = value; K*M1$@5
} UDPn4q
h r6?9RJY
(UZ].+)s
public int getNSplitter() Sx1OY0)s
{ "i&9RA!1
return nSplitter; f[?JLp
} BC#O.93`
(~fv;}}v
ep{/m-h(!_
public void setNSplitter(int nCount) Xm<|m#
{ +]Ev
nSplitter = nCount; DeI3(o7
} u[nLrEnD
} ^OK;swDW
9zm2}6r4
QkYKm<b
/* NTVaz.
**Utility.java 9)uJ\NMy
*/ At&kW3(
package NetFox; 8EU/}Ym
,x?Jrcx~'C
< Yc)F.:
public class Utility { -8v:eyc
{:=]J4]
D58RHgY[
public Utility() 6_K7!?YG7
{ AB<%GzW0(
NHe[,nIV
3CPSyF
} Hxn#vAc
!t?5U_on
//线程睡眠 |O;vWn'U2
public static void sleep(int nSecond) R:[#OH.c
{ H#G3CD2&
try{ 7c8`D;A-K
Thread.sleep(nSecond); u"8KH u5C@
} #VxN [770
catch(Exception e) <`NtTG
{ t_+owiF)M
e.printStackTrace (); yh'*eli
} <v?2p{U%
} y2R\SL,
H|/"'t OZ
//日志 VO /b&%
public static void log(String sMsg) g+Y &rz
{ a6?t?:~|
System.err.println(sMsg); { T<[-"h
} {U4{v=,!I
|hX\ep
R7c42L\QA
public static void log(int sMsg) D`U,T&@
{ qCq?`0&#
System.err.println(sMsg); n*Hx"2XF
} @VyF' ?}
} QHd|cg
,rOh*ebF
:d~mlyFI6P
/* uc LDl
**TestMethod.java \\{78WDA
*/ %BQ?DTtb7'
package NetFox; W,:j>vg
09i77
Vddod
public class TestMethod { XANJA
3ouo4tf$H.
)JU`Z@?8
public TestMethod() rS+ >oP}
{ ///xx/weblogic60b2_win.exe olm'_{{
try{ ZgmK~iJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {fY(zHC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >y$*|V}k
SiteFileFetch fileFetch = new SiteFileFetch(bean); =E:sEw2j
fileFetch.start(); 4b}'W}
} NOf{Xx<#k
catch(Exception e){e.printStackTrace ();} N:EljzvP}
=6N=5JePB
fc4jbPp:M
} 3@* ~>H
Iz&d S?p_
?"kU+tCxg
public static void main(String[] args) =@nW;PUZ
{ G0Z$p6z
new TestMethod(); @Ph'!
} ]qx!51S
} ^;$9>yi1
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