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)); n>aH7
} Os"T,`F2s
for(int i=0;i<nEndPos.length-1;i++) D~LU3#n
{ ?fmW'vs
nEndPos = nStartPos[i+1]; 8xQjJ
} J'#R9NO<
nEndPos[nEndPos.length-1] = nFileLength; mqk tM6
} 6;{E-y
} 3~6,fTMz{
6BIr{SY
j#[%-nOT
//启动子线程 v!77dj 6I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hR(p{$-T
for(int i=0;i<nStartPos.length;i++) sTChbks
{ :1,xse
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1y}tPkOe7O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7zEpuw
nStartPos,nEndPos,i); 6V^KOG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WSV[)-=:
fileSplitterFetch.start(); I^itlQ
} WuUT>omH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fOkB|E]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )3A%Un#B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /o]j
nEndPos = " + nFileLength); |VE*_G
// fileSplitterFetch[nPos.length-1].start(); fgEMn;
Bn?MlG;aA
+U= !svE
//等待子线程结束 V^5Z9!
//int count = 0; EGIwqci:
//是否结束while循环 XX|wle1Kg
boolean breakWhile = false; tj;<EaM
QLum=YB
nk^-+olm
while(!bStop) o dTg.m
{ vB;$AFh{
write_nPos(); Cv;\cI"&
Utility.sleep(500); 8j<+ ' R
breakWhile = true; k:k!4
Kt/Wd
Fl;!'1
for(int i=0;i<nStartPos.length;i++) g"o),$tm
{ OJ2I (8P
if(!fileSplitterFetch.bDownOver) RRBBz7:~
{ **L3T3$)
breakWhile = false; 8w]>SEGFs
break; r(ufyC&
} O| zLD
} aq<QKnU
if(breakWhile) v'W`\MKY)
break; W99Hq1W;r
]53'\TH
@!zT+W&
//count++; HG)c\b
//if(count>4) # 5C)k5
// siteStop(); Qpaan
} 8`S6BkfC|
SP |R4*KY
'-k~qQk)6
System.err.println("文件下载结束！"); JD1D(
} e+=IGYC
catch(Exception e){e.printStackTrace ();} 4hh=z>$|l)
} RS`~i8e'
e:H9!
?=X_a{}/
//获得文件长度 8NS1*\z
public long getFileSize() ^S'tMT_
{ u]%>=N(^2
int nFileLength = -1; t4E=
try{ h]z>H~.<*
URL url = new URL(siteInfoBean.getSSiteURL()); <dA1n:3o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U&<Nhh
httpConnection.setRequestProperty("User-Agent","NetFox"); ZD'fEqM
E?+MM0
xHMbtY
int responseCode=httpConnection.getResponseCode(); "p{cz(
if(responseCode>=400) =P.m5e<
{ umo@JWr
processErrorCode(responseCode); wWNHZv&
return -2; //-2 represent access is error 6Wabw:
} @xI:ZtM
A/4HR]
3_]<H<w
String sHeader; $SmmrM
P95A_(T=[
\dz@hJl:
for(int i=1;;i++) HX3R@^vo
{ \|}dlG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '~ {xn
//Utility.log(in.readLine()); ]O\Oj6C
sHeader=httpConnection.getHeaderFieldKey(i); 4mY(*2:HC
if(sHeader!=null) -OS&(7
{ 9(/ ;Wutj"
if(sHeader.equals("Content-Length")) S^Z[w|1
{ oe:@7stG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9O+><x[i
break; R""P01IZH
} ?(^HjRUY
} fiq4|!^h
else !Bv"S0
break; v3i]z9`
} p(F}[bP
} wf<=rW'
catch(IOException e){e.printStackTrace ();} Z/wKUK;
catch(Exception e){e.printStackTrace ();} K;u<-?En
{5=Iu\e
HCI|6{k
Utility.log(nFileLength); &O'6va
lKd+,<
X&[S.$_U
return nFileLength; E2s lpo
} {/C \GxH+
k(oHmw
`;ofQz4
//保存下载信息（文件指针位置） 6_m5%c~;+r
private void write_nPos() }jQxwi)
{ hy"O_Le
try{ 0Jh^((i*
output = new DataOutputStream(new FileOutputStream(tmpFile)); * ?a-m\
output.writeInt(nStartPos.length); g{zvks~it
for(int i=0;i<nStartPos.length;i++) 9U_uw Rv2
{ \G?GX
// output.writeLong(nPos); @{_L38. Nw
output.writeLong(fileSplitterFetch.nStartPos); zqDIwfW
output.writeLong(fileSplitterFetch.nEndPos); "eq{_4dL
} B>3joe}
output.close(); JM-spi o
} hlpi-oW`
catch(IOException e){e.printStackTrace ();} 9 wun$!>&
catch(Exception e){e.printStackTrace ();} ,&$+{3
} 2g elmQnc
kCXQHX
R^PPgE6!$
//读取保存的下载信息（文件指针位置） vps</f!
private void read_nPos() W0X/&v,k*
{ gBzg'Z
try{ [*<F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .5ap9li]
int nCount = input.readInt(); P8N`t&r"7
nStartPos = new long[nCount]; U{vt9t
nEndPos = new long[nCount]; g-0?8q5T6
for(int i=0;i<nStartPos.length;i++) Wj"\nT4
{ 4+ BWHV
nStartPos = input.readLong(); @l)HX'z0d
nEndPos = input.readLong(); mXd,{b'
} qB57w:J
input.close(); 2lVJ"jg
} 6>rgoT)6~
catch(IOException e){e.printStackTrace ();} CdCo+U5z{
catch(Exception e){e.printStackTrace ();} Yj/aa0Ka4
} @6eM{3E.
G%{J.J41F
:.863_/
private void processErrorCode(int nErrorCode) LUGyc( h
{ _i_^s0J
System.err.println("Error Code : " + nErrorCode); A>@ i TI
} ~)\9f 1O{^
{tUjUwhz(
q\2q3}n
//停止文件下载 EwvW: t1
public void siteStop() B$R"Ntp
{ ftS^|%p
bStop = true; Y$3 &?LA
for(int i=0;i<nStartPos.length;i++) d5zv8?|X+
fileSplitterFetch.splitterStop(); +Bg$]~T
Tm!pAD
Sz_bjhyT}
} ({XB,Rm
} [D!-~]5
//负责部分文件的抓取 T bMW?Su
**FileSplitterFetch.java ETt7?,x@
*/ ;VhilWaF-
package NetFox; BE`{? -G
]mDsd*1
qH#?, sK ^
import java.io.*; ,8~qnLy9
import java.net.*; +m|S7yr'
0GEM3~~D.?
'R'P^
public class FileSplitterFetch extends Thread { 7R4sd
:c4iXK0_^?
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String sURL; //File URL >3{#S:
long nStartPos; //File Snippet Start Position B|\pzWD%
long nEndPos; //File Snippet End Position _ELuQ>zM]+
int nThreadID; //Thread's ID iLQFce7d|&
boolean bDownOver = false; //Downing is over :%_*C09
boolean bStop = false; //Stop identical vJybhdvP
FileAccessI fileAccessI = null; //File Access interface U/hf?T;
c[p>*FnP
fN)A`>iP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pD^7ZE6
{ BHmmvbM#Qm
this.sURL = sURL; 1!(Og~#(
this.nStartPos = nStart; <1t.f}}uX
this.nEndPos = nEnd; mEL<d,XhI
nThreadID = id; 1L~y!il
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~>&Jks_Q
} $&fP%p
7D5[ L
NOC8h\s}(
public void run() *d~).z)
{ i5PZ)&
while(nStartPos < nEndPos && !bStop) QcW6o,
{ wSy|h*a,
jN3K= MA
@ Sq =q=S
try{ XZh1/b^DMN
URL url = new URL(sURL); U?@ s`.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )JNUfauyT
httpConnection.setRequestProperty("User-Agent","NetFox"); H0!LiazA>
String sProperty = "bytes="+nStartPos+"-"; <0EVq8h
httpConnection.setRequestProperty("RANGE",sProperty); Zqo
Utility.log(sProperty); B//2R)HS
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-0I]Sm;$
InputStream input = httpConnection.getInputStream(); VVd9VGvh
//logResponseHead(httpConnection); =3~5I&
3]46qk'
=,MX%-2
byte[] b = new byte[1024]; W"{:|'/v
int nRead; n]3Lqe;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `>HM<Nn-0
{ [Sj _=
nStartPos += fileAccessI.write(b,0,nRead); #<$pl]>}t
//if(nThreadID == 1) !~j-5+DI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {wp~
} l:@`.'-=
7>-"r*W +z
. r?URC
Utility.log("Thread " + nThreadID + " is over!"); R!+_mPb=Q*
bDownOver = true; ydZS^BqG
//nPos = fileAccessI.write (b,0,nRead); Qhc>,v)
} b41f7t=
catch(Exception e){e.printStackTrace ();} )yl;i
} d`w3I`P1
} ,J@A5/B,AA
?hFG+`"W
S5+W<Qs
//打印回应的头信息 FQlYCb
public void logResponseHead(HttpURLConnection con) %2I >0
{ Jan~Rran
for(int i=1;;i++) .:~{+ <*`
{ "<N2TDF5
String header=con.getHeaderFieldKey(i); -f-@[;D
if(header!=null) l-gNJ=l+K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lZ*V.-D^]
Utility.log(header+" : "+con.getHeaderField(header)); FJ+n- \
else i-YSt5iq
break; } %bP9
} J$D/-*/@
} Y& p ~8
"9v4'"
W<c95QD.
public void splitterStop() EyDH-}Y
{ fG,)`[eD!_
bStop = true; my}l?S[2d@
} )*`cJ_t
E4cPCQyeH
2v\<MrL
} c}G\F$
VprrklZ
khb/"VYd
/* Gl6M(<f\5
**FileAccess.java -Q MO*PY
*//文件访问(定位，写) 6k6}SlN[
package NetFox; ^Z>Nbzr{
import java.io.*; <HfmNhI85(
\sEH)$R'
T(z/Jm3
public class FileAccessI implements Serializable{ 2{9%E6%#
o:c:hSV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #JYH5:*
RandomAccessFile oSavedFile; 2DXV~>
long nPos; F T$x#>
lcR1FbJ2'
d",VOhW7)S
public FileAccessI() throws IOException O"ebrv
{ H$k2S5,,z
this("",0); 7m.>2U
} E#VF7 9L
VT2f\d[Q
j58'P 5N
public FileAccessI(String sName,long nPos) throws IOException mO0}Go8
{ *[+{KJ
oSavedFile = new RandomAccessFile(sName,"rw"); h#}'9oA
this.nPos = nPos; q^eLbivVE
oSavedFile.seek(nPos); A(D3wctdr
} 'j$n;3
D}OhmOu3
hH~GH'dnaE
public synchronized int write(byte[] b,int nStart,int nLen) Y<;KKD5P'j
{ =Bos>;dl
int n = -1; "Ky&x$dje
try{ 5I&Dk4v
oSavedFile.write(b,nStart,nLen); 7qLB9r
n = nLen; x-s\0l
} Y-.aSc53
catch(IOException e) 34I;DUdcE
{ YM&i
e.printStackTrace (); 3a0% J'
} }t0JI3
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o]aMhSol
return n; 30bdcDm,
} fS]Z`U"
jE2EoQi,
>9,LN;Ic
} Huc|HL#C
P-\65]`C
ltlnXjRUv
/* L}VQc9"gc
**SiteInfoBean.java Qov*xRO6
*/ E&;;2
package NetFox; y]}N[l
P\%aJ'f~
;v5Jps2^]
public class SiteInfoBean { 0QY9vuhL<
h*V~.H
Xb.# =R
private String sSiteURL; //Site's URL +&[X7r<
private String sFilePath; //Saved File's Path {yM@3v~
private String sFileName; //Saved File's Name )CD-cz6n
private int nSplitter; //Count of Splited Downloading File XnB-1{a1
bd&Nf2
]Cp`qayct
public SiteInfoBean() P,)\#([vc
{//nSplitter的缺省值为5 z}-8pDD'
//default value of nSplitter is 5 A\v]ZN4
this("","","",5); [Uw3.CVh
} ,"f2-KC4h
pg3h>)$/
.[o`TlG%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .q'{3
{ F6Qnz8|
sSiteURL= sURL; @;Xa&*
sFilePath = sPath; O+=C8
sFileName = sName; [fg-"-+:M
this.nSplitter = nSpiltter; Wb;D9Z
CK8!7=>}^
MS& 'Nj
} `%$+rbo~
ldr~=<hsZ
+0M0g_sk
public String getSSiteURL() R0T{9,;[`
{ S'=}eeG
return sSiteURL; I[P_j`aE
} {YEGy
ORhvo,.u
cQq78Lo
public void setSSiteURL(String value) sfs2kiH
{ QW2SFpE
sSiteURL = value; KVPWJHGr
} vvF]g.,
Q:j)F|uhc
newURb,-!
public String getSFilePath() \`-a'u=S
{ {tUxRX
return sFilePath; ageTv/
} !mK}Rim~
1B~[L 5p9
e,T^8_>
public void setSFilePath(String value) {11xjvAD
{ )^m"fQ+
sFilePath = value; C'a#.LM
} af|x(:!H
j{Sbf04
"6>+IF
public String getSFileName() FLLfTkXdI
{ ~r&+18Z;
return sFileName; X;CRy,
} WZcAwYB
oq2-)F2/
w6|l ~.$=
public void setSFileName(String value) U;LX"'}
{ d?N[bA
sFileName = value; .yQ<
} r>J%Eu/O
%Q zk aXJ
$j/#IzD1D
public int getNSplitter() t]8nRZ1
{ CB`GiH/j
return nSplitter; X08[,P#I
} WMnxN34
cq}i)y
VbX$\Cs:
public void setNSplitter(int nCount) lA n^)EL
{ -lb%X3`
nSplitter = nCount; a"phwCc"%
} ^tI4FQ>Y
} NGmXF_kqN
S0?e/VWy
petq6)g?
/* .Zr3!N.t
**Utility.java C;oO=R3r
*/ ?~/_&=NSx
package NetFox; ](>YjE0
rAS2qt
;I~UQgE6H
public class Utility { aEdc8i?
,soXX_Y>
/@0
public Utility() QG5)mIJ
{ CIAKXYM
rmPJid[8B~
#=#bv`
} P7*?E*
C@ "l"
//线程睡眠 _g6H&no[
public static void sleep(int nSecond) ;TboS-Y
{ kcE86Y=|x!
try{ tLM/STb6
Thread.sleep(nSecond); J/\^3rCB
} 4Q~++PKBe
catch(Exception e) I|_U|H!`
{ p?sFX$S
e.printStackTrace (); pPJE.[)V/
} $|7;(2k
} yvV]|B@sO
{z7kW@c
//日志 =xRxr@
public static void log(String sMsg) +3o 4KB}
{ ;#S4$wISw`
System.err.println(sMsg); jn#Ok@tZ
} A:,R.P>`C
-ZBSkyMGy
XMm(D!6
public static void log(int sMsg) wPH1g*U
{ H263<^
System.err.println(sMsg); S")*~)N@
} &1ss @-
} J3AS"+]
6x"|,,&MD0
$iOkn|~<@W
/* *;<>@*
**TestMethod.java bTc'E#
*/ Fn*)!,)
package NetFox; 7"$9js2
X1\ao[t<;c
%!p/r`
public class TestMethod { F+::UWKA
h/\/dp/tt
~6Df~uN
public TestMethod() ~VaO,8&+L
{ ///xx/weblogic60b2_win.exe _dynqF8*
try{ 5.FAuzz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xsv^GmP+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k{B;J\`E;
SiteFileFetch fileFetch = new SiteFileFetch(bean); +B-;.]L T
fileFetch.start(); F)4;:".zna
} J)a^3>
catch(Exception e){e.printStackTrace ();} 1[H1l;
?)'+l
qlIbnyP<
} rc)vVv
`KzNBH,W
b1frAA
public static void main(String[] args) TrmU
{ zHW}A `Rz
new TestMethod(); oEnCe
} [wR x)F"
} 'Z ,T,zW
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