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)); @>*r2=#14
} `y>BbJqy
for(int i=0;i<nEndPos.length-1;i++) &$bcB]C\3
{ '>cZ7:
nEndPos = nStartPos[i+1]; O1Ynl`}
} }Gva=N:
nEndPos[nEndPos.length-1] = nFileLength; h0] bIT{
} \ [bJ@f*."
} .B?fG)'WsF
cHC1l
l6- n{zG
//启动子线程 ^+w1:C5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v:"Y
for(int i=0;i<nStartPos.length;i++) l}@C'Np
{ 3aw-fuuIb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9^7z"*@#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4k!>JQor
nStartPos,nEndPos,i); WCY5F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T9FGuit9
fileSplitterFetch.start(); 2y IDyo
} ;o158H$gz;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [>LO'}%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iUbcvF3aP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iD.p KG
nEndPos = " + nFileLength); cx[[K.
// fileSplitterFetch[nPos.length-1].start(); xFcW%m>9C
):\+%v^
}{}?mQ
//等待子线程结束 wbB\~*Z)
//int count = 0; e=+q*]>
//是否结束while循环 :w]NN\
boolean breakWhile = false; %Z8wUG
T|p%4hH
1{Ik.O)
while(!bStop) l{QlJ>%~{;
{ BCO (,k
write_nPos(); m2HO .ljc
Utility.sleep(500); OaKr_m
breakWhile = true; tkQrxa|
oT|:gih5
@~&|BvK% \
for(int i=0;i<nStartPos.length;i++) M< H+$}[
{ 'U,\5jj'Y
if(!fileSplitterFetch.bDownOver) 558!?kx$
{ sf O{.#5<
breakWhile = false; ]E.\ |I(
break; FE1'MUT_
} Y.q$"lm7k
} F-XMy>9
if(breakWhile) XZ2 ji_D
break; w\M"9T
fZ(k"*\MZ
cT@H49#uB
//count++; K#Xl)h}y7
//if(count>4) O;$}j:;KF
// siteStop(); p0D@O_ :5
} |9Y~k,rF
y7,t"XV
Kpkpr`:)]
System.err.println("文件下载结束！"); 9VMk?
} &;RBG$t
catch(Exception e){e.printStackTrace ();} @YVla!5O@
} (G~ME>
H6Ytp^~>
_0y]U];ce
//获得文件长度 dGUiMix{N
public long getFileSize() \~r_S
{ 8?rq{&$t
int nFileLength = -1; e:K'e2
try{ 0$i\/W+
URL url = new URL(siteInfoBean.getSSiteURL()); OnyAM{$g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T+PERz(
httpConnection.setRequestProperty("User-Agent","NetFox"); `4e| I.`^r
Y5y7ONcn
ix38|G9U
int responseCode=httpConnection.getResponseCode(); qeC^e}h
if(responseCode>=400) ~i.rk#{?D
{ EN__C$
processErrorCode(responseCode); KpIY>k
return -2; //-2 represent access is error fm$Qd^E|e
} (w`_{%T
a5(9~.9
11Uu5e!.
String sHeader; pU<GI@gU
S~W;Ld<>fB
efuiFN;
for(int i=1;;i++) AF,;3G
{ wc#k@"2AZb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r*ziO#[
//Utility.log(in.readLine()); 2km0
sHeader=httpConnection.getHeaderFieldKey(i); TxH amI l
if(sHeader!=null) og_ylCh:
{ : rudo[L
if(sHeader.equals("Content-Length")) 'UTMEN&
{ nGsFt.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JE#H&]
break; =@&>r5W1
} s@g _F
} 7#N ?{3i
else "Xl"H/3r
break; jAovzZ6BL
} %zR5q Lb
} [;l;kom
catch(IOException e){e.printStackTrace ();} 3#aLCpVla
catch(Exception e){e.printStackTrace ();} ^5)=)xVF
{E}D6`{
~fs} J
Utility.log(nFileLength); #ApmJLeCO
4;(W0RQa
CtUAbR
return nFileLength; 9?^0pR p
} ]AZCf`7/?
6G(K8Q{>
9ph>4u(R
//保存下载信息（文件指针位置） (4IP&^j:\
private void write_nPos() $@w,9J\
{ ^E)8Sb9t
try{ zn0%%x+!g
output = new DataOutputStream(new FileOutputStream(tmpFile)); oTr,zRL
output.writeInt(nStartPos.length); CYsLyk
for(int i=0;i<nStartPos.length;i++) %s;5
{ EpTc{
// output.writeLong(nPos); o5YL_=7m
output.writeLong(fileSplitterFetch.nStartPos); j3S!uA?
output.writeLong(fileSplitterFetch.nEndPos); ?T,a(m<i{
} ~mZ[@Z
output.close(); fhha-J
} YgtW(j[
catch(IOException e){e.printStackTrace ();} O&#>i]*V
catch(Exception e){e.printStackTrace ();} b?<@
} f3s4aARP
vbtjPse
eT?vZH[N
//读取保存的下载信息（文件指针位置） sQ&<cBs2
private void read_nPos() C0khG9,BL
{ 7W+{U02O
try{ :G=ol2Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e&K7n@
int nCount = input.readInt(); r1z+yx
nStartPos = new long[nCount]; p^Z|$aZZ
nEndPos = new long[nCount]; [.$/o}
for(int i=0;i<nStartPos.length;i++) p9!jM\(
{ A;e"_$yt8
nStartPos = input.readLong(); `=kiqF2P}
nEndPos = input.readLong(); I]cZcx,<q
} #Fgybokm
input.close(); 2Ky|+s[`[
} {bC(>k|CQ
catch(IOException e){e.printStackTrace ();} P,7R/-u5D
catch(Exception e){e.printStackTrace ();} jF(R;?,
} ]vw%J ^7:a
p _2Yc]8
uTdz$Nh
private void processErrorCode(int nErrorCode) 7.+vp@+
{ {IF$\{Al
System.err.println("Error Code : " + nErrorCode); QHsJo|.
} cV7a, *
BqavI&1=
AbQnx%$u
//停止文件下载 Fr<tk^~/
public void siteStop() 0d89>UB-8q
{ H> n;[
bStop = true; |Qpd<L
for(int i=0;i<nStartPos.length;i++) g6$\i m
fileSplitterFetch.splitterStop(); _s:5)
hVCxwTg^X
e?\hz\^
} rKTc6h:)
} y>cT{)E$
//负责部分文件的抓取 X|4Kdi.r@
**FileSplitterFetch.java B->oTC`5
*/ &KV$x3
package NetFox; B-|C%~fe
DD6K[\
6aWNLJ@
import java.io.*; V<U9Pj^?^
import java.net.*; q AsTiT6r
`'9t^6mk
cKIA.c}N
public class FileSplitterFetch extends Thread { n:}'f- :T
er@.<Dc
l=a<=i
String sURL; //File URL hn$jI5*`
long nStartPos; //File Snippet Start Position /8,cF7XL*
long nEndPos; //File Snippet End Position II\}84U2 .
int nThreadID; //Thread's ID ?9T,sX:
boolean bDownOver = false; //Downing is over :#UA!|nV
boolean bStop = false; //Stop identical M?DXCsZ,)s
FileAccessI fileAccessI = null; //File Access interface G*-7}7OAs
BDX>J3h
UI wTf2B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a!&m\+?
{ |T*t3}
this.sURL = sURL; dd@ D s
this.nStartPos = nStart; vtzbF1?O
this.nEndPos = nEnd; 6rlM\k@!
nThreadID = id; b86c[2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;Wn0-`_1,
} y+7A?"s)
"rrE_
iE]^6i
public void run() I@1VX5
{ :Yi 4Ia
while(nStartPos < nEndPos && !bStop) H.O&seY
{ y#nyH0U
Nig)!4CG
7!e kINQ
try{ /g!X[rn7Q
URL url = new URL(sURL); !1<>][F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JP]-a!5Ru
httpConnection.setRequestProperty("User-Agent","NetFox"); 8vj]S5
String sProperty = "bytes="+nStartPos+"-"; m'2EiYX$}\
httpConnection.setRequestProperty("RANGE",sProperty); )-i(%;,*e
Utility.log(sProperty); #BI6+rfv|
, lBHA+@
}dEf |6_
InputStream input = httpConnection.getInputStream(); Slp_o\s$@
//logResponseHead(httpConnection); `Tr !Gj_
%.:]4jhk
3B4C@ {
byte[] b = new byte[1024]; i}C%`1+(
int nRead; zB6&),[,v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9"dZ4{\!
{ ,!98VJmr
nStartPos += fileAccessI.write(b,0,nRead); bGik~
//if(nThreadID == 1) .0dx@Sbv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F[X;A\
} ALKzR433/
c}2"X,
)2F%^<gZ#
Utility.log("Thread " + nThreadID + " is over!"); hM8FN
bDownOver = true; |W SvAM3
//nPos = fileAccessI.write (b,0,nRead); ?u{D-by%&
} P_Exh]P
catch(Exception e){e.printStackTrace ();} F&OcI.OTXF
} ]/Cu,mX
} 2'?C
`yM9XjEl>
?cD_\~
//打印回应的头信息 "@itn
public void logResponseHead(HttpURLConnection con) nwJc%0
{ ?Lr:>
for(int i=1;;i++) l YjPrA]TC
{ KwxJ{$|xH
String header=con.getHeaderFieldKey(i); )u307Lg
if(header!=null) +4k4z:<n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?T>NvKF
Utility.log(header+" : "+con.getHeaderField(header)); }G<A$*L1
else T>v`UN Bl]
break; }vW3<|z
} (y2P."
} mXUe/*r0T
&G7@lz@sK+
eS2VLVxu
public void splitterStop() 9YwS"~Q =w
{ =jvN8R*[
bStop = true; q94*2@KV
} 2VkA!o4nP
K$-|7tJon
22D,,nC0+=
} B_0]$D0 ^
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ZIaFvm&q7Z
/* u6/;=]0
**FileAccess.java R)9FXz$).
*//文件访问(定位，写) >fgV!o4
package NetFox; wM#q [m;
import java.io.*; _;k))K^
Le,+jm
~h444Hp=
public class FileAccessI implements Serializable{ \3cg\Q+~
OLDEB.@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UG,n q
RandomAccessFile oSavedFile; 1i$OcN?x%
long nPos; TK#-;p_
Oz.Zxw
\LDcIK=
public FileAccessI() throws IOException oX[I4i%G
{ (9!kKMQW'
this("",0); :$oiP
} s *<T5Z
`wNJ*`
i$4lBy_2
public FileAccessI(String sName,long nPos) throws IOException q<A,S8'm
{ 7x`4P|Uu
oSavedFile = new RandomAccessFile(sName,"rw"); ,+RoJwi m
this.nPos = nPos; 2$oGy
oSavedFile.seek(nPos); CIf""gL9
} Xd9<`gu
W7 9.,#
Bqb3[^;~
public synchronized int write(byte[] b,int nStart,int nLen) M,N(be-
{ $dHD
int n = -1; SwmX_F#_
try{ +,bgOq\aG
oSavedFile.write(b,nStart,nLen); p9iCrqi
n = nLen; _ 4+=S)$
} ]Oe[;<I
catch(IOException e) m{0u+obi&w
{ JT 5+d ,
e.printStackTrace (); e irRAU
} n/GJ&qLi:g
%Lgfi
vX}mwK8
return n; }i2dXC/
} SlUt&+)
s&qr2'F+z
&bS!>_9
} TWTRMc;z+
IN94[yW{1
~7&O[
/* y1hJVYE2
**SiteInfoBean.java ki|w?0s
*/ j_~lc,+m
package NetFox; '#x<Fo~hT
Q$DF3[NC
MYeGr3V3
public class SiteInfoBean { c9;oB|8|
gc{5/U9H*
Dv+:d4|"
private String sSiteURL; //Site's URL `z3"zso
private String sFilePath; //Saved File's Path BcD%`vGJ
private String sFileName; //Saved File's Name e\>g@xE%
private int nSplitter; //Count of Splited Downloading File 2E}^'o
=;HmU.Uek%
+v'n[xa1v
public SiteInfoBean() `pd1'5Hm
{//nSplitter的缺省值为5 ;V3d"@R,
//default value of nSplitter is 5 `o!a RX
this("","","",5); +)K yG
} 1Du9N[2'P
b1qli5
jRIm_)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ph=[|P)
{ 4WV)&50
sSiteURL= sURL; ) XHcrm&
sFilePath = sPath; _i{4 4zE
sFileName = sName; VR0#"
this.nSplitter = nSpiltter; t~"DQqE
]6{\`a
E.~~.2
} uu582%tiG
B 9AE*
W4(O2RU
public String getSSiteURL() [u2)kH$
{ {01wW1
return sSiteURL; ihdtq
} b`sph%&
>jDx-H.N
S=~8nr/V
public void setSSiteURL(String value) bwAL:
{ mF !=H%
sSiteURL = value; CiGN?1|
} 3 ,?==?
Aw *:5I[
k)R>5?_
public String getSFilePath() c F(]`49(
{ JP<Z3 A2q
return sFilePath; ~0>{PD$@
} <=,KP)
>h m<$3
wc'K=;c
public void setSFilePath(String value) lCyp&b#(L
{ XL7jUi_4:L
sFilePath = value; n`hes_{,g
} s~6irf/
L"6@3
kY6))9 O
public String getSFileName() -m~[z
{ e?D,=A4mV"
return sFileName; D0&{iZ(
} z[wk-a+w
Kv:ih=?
Zb7:qe<UN
public void setSFileName(String value) aJDu_
{ RFu]vFff
sFileName = value; c!%:f^7g
} 'HV}Tr
o*u A+7n
,uP1U@Cas
public int getNSplitter() AcF;5h
{ G#4cWn'
return nSplitter; `&U ['_%
} gU}?Yy
7M1*SC
T<0Bq"'%
public void setNSplitter(int nCount) :q4Mnr
{ "zO+!h'o
nSplitter = nCount; i4"xvLK4
} FBPT@`~v
} |JL47FR
]eq3cwR[|
\0pJ+@\T9
/* .j4IW3)
**Utility.java 5aTyM_x
*/ O,[aL;v
package NetFox; X3Vpxtb
w`VmN}pR
y o[!q|z
public class Utility { |[TH ~o
sh?Dxodp9
V@K}'f~
public Utility() x9HA^Rj4-
{ &w3LMOT
8X]j;Rb
z@ A5t4+3
} q6{%vd
)x"Z$jIs
//线程睡眠 H2RNekck
public static void sleep(int nSecond) ,Fg&<Be}Jx
{ 0r=Lilu{q
try{ y\@;s?QL
Thread.sleep(nSecond); ASaG }h
} !U/:!e`N
catch(Exception e) (.!q~G
{ N1(}3O
e.printStackTrace (); SJ7>*Sa(u$
} Z-H Kdv!d
} u6jJf@!ws
(s{%XB:K
//日志 Af0E_
public static void log(String sMsg) a@,tf'Sr
{ Zk}e?Grc
System.err.println(sMsg); ?#D@e5Wf
} Z#;ieI\
e= "/oo
a+mq=K
public static void log(int sMsg) lLtC9:
{ ^O\tN\g;c
System.err.println(sMsg); aM.l+DP
} foE2rV/Y
} O,JthlAV4
=OO_TPEZ
kZGhE2np
/* r:Cad0xj;^
**TestMethod.java Q:VD2<2
*/ ,bmTBZV
package NetFox; a$t [}D2
nhXa&Nro
rmQGzQnun
public class TestMethod { /yrR f;}<O
x_Ais&Gc
iJrscy-
public TestMethod() o ohf))
{ ///xx/weblogic60b2_win.exe +bf%]
try{ |klL KX&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pdnL~sv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N'm:V
SiteFileFetch fileFetch = new SiteFileFetch(bean); PLo.q|%
fileFetch.start(); Z*]n]eS
} _TQt!Re`,
catch(Exception e){e.printStackTrace ();} ~?b(2gn
sQihyq6U;
J;q3 fa
} ]P<&CEk
/e{Oqhf[n
( v ~/glf
public static void main(String[] args) 4N` MY8',
{ #2HygS
new TestMethod(); aeBth{
} 1NOz $fW
} 'OX6eY5
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