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)); OMY^'g%w
} &UFj U%Z%
for(int i=0;i<nEndPos.length-1;i++) =q\Ghqj1
{ r(ZMZ^
nEndPos = nStartPos[i+1]; Ye=c;0V(w
} ?hFG+`"W
nEndPos[nEndPos.length-1] = nFileLength; >s%&t[r6
} 6_=t~9sY
} B4#XQ-
P&snIJ
ov 'g'1}
//启动子线程 >h Rq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t}Q PPp y
for(int i=0;i<nStartPos.length;i++) X/8TRiTFv
{ 2Wx~+@1y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qi;62M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K,f"Q<sU%
nStartPos,nEndPos,i); mNQ~9OJ1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nb30<h
fileSplitterFetch.start(); 0en Bq>vr
} _xmS$z)TO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {qJ(55
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x:? EL)(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pba`FC4R
nEndPos = " + nFileLength); IaHu$` v
// fileSplitterFetch[nPos.length-1].start(); ` it<\r[=
>zS<1
o>l/*i0I
//等待子线程结束 rw }wQP_'
//int count = 0; Zl\$9Q_
//是否结束while循环 -;Ij ,
boolean breakWhile = false; q; ?Kmk
,]LsX"u
L; o$vI~U,
while(!bStop) 1$S`>M%a
{ 2v\<MrL
write_nPos(); H/^t]bg,
Utility.sleep(500); sK/Z'h{|
breakWhile = true; @Rw]boC
yEPkF0?
t%fcp
for(int i=0;i<nStartPos.length;i++) (7*((
{ B.#.gB#C
if(!fileSplitterFetch.bDownOver) eJy}W /
{ >4G~01
breakWhile = false; Q3'L\_1L
break; <HfmNhI85(
} <-(n48
} \sEH)$R'
if(breakWhile) >mW*K _~
break; h|{DIG3
CeINODcT
o:c:hSV
//count++; nr?|!gj
//if(count>4) m85Hx1!p.
// siteStop(); ~vscATQ
} 0..]c-V(G
3Hi[Y[O`%P
IIY3/
System.err.println("文件下载结束！"); |@Ze{\
} z5g4+y,
catch(Exception e){e.printStackTrace ();} ] L6LB\
} nc9sfH3
<3fY,qw
9#:B_?e=
//获得文件长度 5_+pgJL
public long getFileSize() L(q~%
{ Ve[[J"ze
int nFileLength = -1; 43s8a
try{ )ZMR4U$+v
URL url = new URL(siteInfoBean.getSSiteURL()); 9CFh'>}$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :;URLl0
httpConnection.setRequestProperty("User-Agent","NetFox"); Zv5vYe9Ow
XR+
zrL+:/t
int responseCode=httpConnection.getResponseCode(); q^eLbivVE
if(responseCode>=400) nC5]IYL|
{ VLcwBdo
processErrorCode(responseCode); ly::?
return -2; //-2 represent access is error 6=p!`DOd
} h'"~t#r
hH~GH'dnaE
62 9g_P)
String sHeader; (b"kN(
=Bos>;dl
7{Zs"d{s
for(int i=1;;i++) !7n`-#)
{ 5BS !6o;P'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rAZ~R PrW
//Utility.log(in.readLine()); 4G'-"u^g
sHeader=httpConnection.getHeaderFieldKey(i); z#GrwE,r
if(sHeader!=null) =h\uC).t&
{ yqKSaPRA
if(sHeader.equals("Content-Length")) ziXI$B4-
{ 6 2LLfD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vtv1{/@+c
break; OjurfVw
} .s%dP.P:i1
} i$6o>V6
else 8<=]4-X@
break; IqCh4y3
} ]2rCn};
} $ qTv2)W1{
catch(IOException e){e.printStackTrace ();} ,*Z/3at}5M
catch(Exception e){e.printStackTrace ();} d Z}|G-:
4l@aga
JOo+RA5d
Utility.log(nFileLength); OU[ FiW-E
|&_(I
tPChVnB
return nFileLength; P-\65]`C
} 3'!*/UnU
IweNe`Z
vu~7Z;y(<j
//保存下载信息（文件指针位置） ot,=.%O
private void write_nPos() 'DD~xCXE
{ eQJyO9$G
try{ \u*[mrX_B:
output = new DataOutputStream(new FileOutputStream(tmpFile)); T'-kG"lb
output.writeInt(nStartPos.length); D22A)0+_
for(int i=0;i<nStartPos.length;i++) NEt_UcC
{ W?yGV{#V(=
// output.writeLong(nPos); AWDy_11Nm
output.writeLong(fileSplitterFetch.nStartPos); vlo!D9zsV3
output.writeLong(fileSplitterFetch.nEndPos); ]<k+a-Tt
} "4L_BJZ
output.close(); y3ST0=>j}
} ) ):w`^6
catch(IOException e){e.printStackTrace ();} ({mlA`d]
catch(Exception e){e.printStackTrace ();} NY/-9W5T4
} Uy<n7*H
0RHjA&r3v
>AW&Lfw$
//读取保存的下载信息（文件指针位置） )v %tyU
private void read_nPos() 11B8 LX
{ g^))
try{ `V{'GF&[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /%AA\`:6
int nCount = input.readInt(); "QmlW2ysi
nStartPos = new long[nCount]; f@ .s(i=z
nEndPos = new long[nCount]; =D Tbz3<
for(int i=0;i<nStartPos.length;i++) &%4A3.qE
{ 2+|U!X
nStartPos = input.readLong(); x{3q'2
nEndPos = input.readLong(); IZ@M K
} sOm&7A?
input.close(); {j%7/T{
} o`.5NUn
catch(IOException e){e.printStackTrace ();} %$F_oO7"
catch(Exception e){e.printStackTrace ();} X<d`!,bn@
} #zg"E<
(H-kWT
BOme`0A
private void processErrorCode(int nErrorCode) 3-gy)5.xe
{ SHQgI<D7
System.err.println("Error Code : " + nErrorCode); z q@"qnr
} 9`Xr7gmQf
GriFb]ml"
%JuT'7VB
//停止文件下载 W];l[D<S*
public void siteStop() o)M<^b3KO
{ Wb;D9Z
bStop = true; =QhK|C!$A
for(int i=0;i<nStartPos.length;i++) V82hk0*j
fileSplitterFetch.splitterStop(); (/C 8\}Ox
AQ)J|i
k<
} ' BY|7j~
} Q+dLWFI
//负责部分文件的抓取 AdWP
**FileSplitterFetch.java Is>~P*2Y=
*/ U,V+qnS
package NetFox; ;rC< C
$spk.j
Wux[h8G
import java.io.*; _CG ED{b@
import java.net.*; C /w]B[H
c"pu"t@/Z
gb/<(I )
public class FileSplitterFetch extends Thread { _*n 4W^8
k; ned
#NWS)^&1b
String sURL; //File URL qsdgG1<
long nStartPos; //File Snippet Start Position |)%;B%
long nEndPos; //File Snippet End Position V(0V$&qipc
int nThreadID; //Thread's ID N^zFKDJG
boolean bDownOver = false; //Downing is over TH*}Ja^/
boolean bStop = false; //Stop identical vvF]g.,
FileAccessI fileAccessI = null; //File Access interface lMe+.P|
{GG;/Ns{f-
]\*_}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SzyaVBD3
{ VJgYXPE `
this.sURL = sURL; ?D=C8[NEX
this.nStartPos = nStart; #pk
this.nEndPos = nEnd; @k\npFKQm
nThreadID = id; U&gI_z[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r tH #j
} ^AC2 zC
,YF1*69
.DHQJ|J-1
public void run() cg^=F_h
{ 3+H[S#e:Z
while(nStartPos < nEndPos && !bStop) @j=rSS
{ n"f:6|<
j>#ywh*A
9S8V`aC
try{ vAfYONU
URL url = new URL(sURL); nTr{D&JS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;8yEhar
httpConnection.setRequestProperty("User-Agent","NetFox"); FMz>p1s|dK
String sProperty = "bytes="+nStartPos+"-"; abg`:E
httpConnection.setRequestProperty("RANGE",sProperty); *@g>~q{`
Utility.log(sProperty); Gq{);fq
l]S%k&
HH|N~pBJB
InputStream input = httpConnection.getInputStream(); |};-.}u^`h
//logResponseHead(httpConnection); &[_D'jm+S0
bOD]`*q
hZ-?-F?*@
byte[] b = new byte[1024]; sU"sd7#A
int nRead; ~$m:j];
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l{hO"fzy
{ ISg-?h/
nStartPos += fileAccessI.write(b,0,nRead); 'LC0hoV
//if(nThreadID == 1) kn}bb*eZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f s2}a
} VUzRA"DP|
\2M{R
N$M:&m3^
Utility.log("Thread " + nThreadID + " is over!"); /]9(InM9/
bDownOver = true; rtz ]PH
//nPos = fileAccessI.write (b,0,nRead); rbI 7 3'
} t]8nRZ1
catch(Exception e){e.printStackTrace ();} ,ygDNF
} wLy:S.r
} ];\XA;aOl}
=" pNE#
.GIygU_
//打印回应的头信息 co{i~['u
public void logResponseHead(HttpURLConnection con) op61-:q/
{ 6yd?xeD
for(int i=1;;i++) vPD%5AJN
{ `+@r0:G&v
String header=con.getHeaderFieldKey(i); - @tL]]
if(header!=null) -lb%X3`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U+:Mu]97
Utility.log(header+" : "+con.getHeaderField(header)); [E9)Da_)i
else JN3&(t
break; Gp2Cwyv
} NGmXF_kqN
} o':K4r;
s,-}}6WO
B]:?4Ov
public void splitterStop() 7E;`1lh7
{ vGchKN~_
bStop = true; lf_q6y
} p_CCKU
(Ji=fh+
SyIi*dH
} Nh1, w
*kt%.wPJ
fr8hT(,s)
/* T*92o:^
**FileAccess.java O}X@QG2_
*//文件访问(定位，写) cpM]APF-
package NetFox; aMaqlqf
import java.io.*; U3t)yr h
SbH} cu8
o^Qy71Uj
public class FileAccessI implements Serializable{ '25zb+-
<=@6UPsn2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xw&vi\*m
RandomAccessFile oSavedFile; QsyM[;\j:
long nPos; m.c2y6<=
X)S4vqf}
Kc+TcC
public FileAccessI() throws IOException :a_MT
{ C^*}*hYk$
this("",0); -+kTw06_C
} @-.Tgpe@a
;R^=($X
_g6H&no[
public FileAccessI(String sName,long nPos) throws IOException i7\MVI8
{ ;TboS-Y
oSavedFile = new RandomAccessFile(sName,"rw"); 56H~MnX
this.nPos = nPos; oWBjPsQ
oSavedFile.seek(nPos); 0r]-Ltvl?}
} ?6 "B4%7b
na3lbwq
Ie4Xk
public synchronized int write(byte[] b,int nStart,int nLen) bDnT><eH
{ Wo6C0Z3g}
int n = -1; I|_U|H!`
try{ h&z(;B!;y.
oSavedFile.write(b,nStart,nLen); ;Ngu(es6
n = nLen; L<p.2[3
} >z k6{kC
catch(IOException e) wPaMYxO/
{ DlQ*'PX7
e.printStackTrace (); ]wEFm;N
} s(y=u>
Gg6<4T1
CW?R7A/
return n; -"}nm!j /5
} mw~$;64;a
8jz7t:0
/<CgSW}
} lLN5***47J
[y(<1]i-a
T)MZ`dM
/* E|x t\*
**SiteInfoBean.java FH7l6b,^
*/ lD,;xuQ
package NetFox; TCK<IZKLqK
3($tD*!o
]~\%ANoi
public class SiteInfoBean { _p0G8
3mT6HGSKR
1=mb2A
private String sSiteURL; //Site's URL p s_o:*$l
private String sFilePath; //Saved File's Path 7:n OAN}%
private String sFileName; //Saved File's Name #Wely~
private int nSplitter; //Count of Splited Downloading File D}nIF7r2N
"(vm0@8><
CMU\DO
public SiteInfoBean() j "e]Ui
{//nSplitter的缺省值为5 JF(&+\i<p
//default value of nSplitter is 5 #=czqZw
this("","","",5); -"d&Ow7o
} -x+K#T0Z
d ZxrIWx
MR.c?P?0Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R'h.lX
{ 0>U7]wZKc
sSiteURL= sURL; (`&E^t
sFilePath = sPath; C@rIyBj1g
sFileName = sName; 7?qRz
this.nSplitter = nSpiltter; kw5`KfG9
imZ"4HnPP
u9G
} uex([;y
jGtu>|Gj
&'W ~~ir
public String getSSiteURL() Rz=wInFs
{ \ 6 :7
return sSiteURL; <MgC7S2I
} AO]1`b:
\Z$MH`_nu
rWN%Tai-
public void setSSiteURL(String value) Wrs6t
{ 4[ =C,5r
sSiteURL = value; O.$OLK;v
} sQ8kLS_q8
KvtJtql;
qw}. QwPT
public String getSFilePath() -5MQ/ujQ
{ U&u~i 3
return sFilePath; YI+o:fGC5
} DQ%(X&k
|/~ISB
<E\vc6n
public void setSFilePath(String value) :zsMkdU
{ {i/7Nx
sFilePath = value; !'8jy_<9
} fU^5Dl
7 MG<!U
jF|LPWl
public String getSFileName() !X+}W[Ic^
{ yIqRSqM
return sFileName; _t@9WA;+\
} aHBM9%gV
YAYwrKt
c->?'h23)
public void setSFileName(String value) Y&1Yc)*O
{ p9j2jb,qy
sFileName = value; bipA{VU
} |jyD@Q,4
xH{V.n&v
7!^Zsp^+
public int getNSplitter() KBwY _
{ #s|,oIm
return nSplitter; z_A34@a
} `k~w 14~w
?/^{sW' |
ad`=A V]
public void setNSplitter(int nCount) Jek3K&
{ |#x]/AXa0/
nSplitter = nCount; F7U$7(I2G
} HC(o;,spO
} ?<D1]Xv
Zl{DqC^
b%|6y
/* Pt?d+aBtV
**Utility.java :0(:}V3z\
*/ dyuT-.2
package NetFox; vz`r !xj)
n-:n.JX
!sav~dB)
public class Utility { `;z;=A*
Cp^%;(@
og8"#%
public Utility() ^LAdN8Cbb
{ <k7q9"\4
n/Dk~Q)
xoNn'LF#u
} XMm(D!6
KAm$^N5
//线程睡眠 A?Gk8
public static void sleep(int nSecond) :1e'22[=.
{ JbW!V Y
try{ - xQJY)
Thread.sleep(nSecond); uU#e54^
} e7JZk6GP#9
catch(Exception e) 6cbIs_g
{ CB>O%m[1
e.printStackTrace (); i`" L?3T
} t$5)6zG
} c4xXsUBQk
LJmRa
//日志 FHbw&
public static void log(String sMsg) ~{BR~\D
{ 6+x>g
System.err.println(sMsg); 5.FAuzz
} !-Md+I_
t7b\#o
lr&O@ 5"oy
public static void log(int sMsg) rklK=W z
{ h|Udw3N1L
System.err.println(sMsg); #dm"!I>g
} DF~{i{
} `KzNBH,W
lO5*n|Ic,
D-4\AzIb
/* Vh;P,no#
**TestMethod.java ">NPp\t>/Z
*/ +hKH\]
package NetFox; l?swW+x\
O5?3nYHa
!:w&eFC6
public class TestMethod { PR*qyELu
_4MT,kN
:h60
public TestMethod() |4A938'4j
{ ///xx/weblogic60b2_win.exe ck\gazo~q
try{ Yeb-u+23
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ik Pm,ZN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8f{;oO
SiteFileFetch fileFetch = new SiteFileFetch(bean); \' ;zD-MX
fileFetch.start(); GJIM^
} 0I \l_St@
catch(Exception e){e.printStackTrace ();} TNK~ETE4
o? {rPFR
pxi/ ]6pw
} EHY}gG)
5Bog\mS
r-k,4Yz
public static void main(String[] args) XH{P@2~l
{ DqTp*hI
new TestMethod(); nPo YjQi
} E< Ini'od[
} &Eqa y'
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