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)); eZa7brC|
} 2F*>&n&Db7
for(int i=0;i<nEndPos.length-1;i++) z4_B/Q
{ &!4E3&+2m
nEndPos = nStartPos[i+1]; vrb@::sy0T
} ^k7I+A
nEndPos[nEndPos.length-1] = nFileLength; .?s jr4
} c! kr BS
} ynM:]*~K
+&)/dHbL`]
mvH8hvD9
//启动子线程 G7CkP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TaSS) n
for(int i=0;i<nStartPos.length;i++) [ x+-N7
{ V-#JV@b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A^M]vk%dg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RuYIG?J=/
nStartPos,nEndPos,i); er24}G8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d #1&"(
fileSplitterFetch.start(); Kkovp^G
} 4vi?9MPz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]cP%d-x}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4+>yL+sC%v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :k?`gm$
nEndPos = " + nFileLength); *~ IHVU
// fileSplitterFetch[nPos.length-1].start(); +`wr{kB$~
M2ex 3m
`lE&:)
//等待子线程结束 !m:WoQ/
//int count = 0; Epp>L.?r
//是否结束while循环 sE&nEc
boolean breakWhile = false; kwUUvF7w
kSEA
^A&{g.0
while(!bStop) RQWUO^&e^
{ XdDQ$'*X
write_nPos(); _ZavY<6
Utility.sleep(500); tH;9"z# ~
breakWhile = true; ~SBW`=aP}
Txo{6nd/
[r>hKZU2
for(int i=0;i<nStartPos.length;i++) V C VqUCc
{ i7T#WfF
if(!fileSplitterFetch.bDownOver) JdI*@b2k[
{ V^FM-bg%9
breakWhile = false; cHr]{@7Cs
break; )MIw/
} ;DX{+Z[
} =>PX~/o
if(breakWhile) 9$v\D3<Z
break; 0y<9JvN$9
_:Q^mV=;j
l+6@,TY1U
//count++; hb~d4J=S
//if(count>4) V9<E`C
// siteStop(); h{-en50tN
} Bi fI.2|
_3wJ;cn.
exSwx-zxI
System.err.println("文件下载结束！"); l]DRJ
} F !v01]O
catch(Exception e){e.printStackTrace ();} zQ<&[Tuwa
} 3@eI?(N
o+OX^F0
moVf(7
//获得文件长度 k(>J?\iNW
public long getFileSize() NY?iuWa*g
{ r{yIF~k@
int nFileLength = -1; jyg>'"W
try{ O+XQP!T
URL url = new URL(siteInfoBean.getSSiteURL()); uq:'`o-1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i)@vHh82
httpConnection.setRequestProperty("User-Agent","NetFox"); i-0AcN./p
\K9Y@jnr
bU}!bol
int responseCode=httpConnection.getResponseCode(); [uie]*^
if(responseCode>=400) z}5'TV=^
{ Tz&cm=
processErrorCode(responseCode); {QK9pZB
return -2; //-2 represent access is error _jkJw2+s\
} Q4ii25]*
:1iXBG\
V/OW=WCzN
String sHeader; c$A}mL_
,,9vk\
QBoX3w=
for(int i=1;;i++) `~=Is.V[
{ f}FJR6VO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U_B`SS
//Utility.log(in.readLine()); WFeaX7\b
sHeader=httpConnection.getHeaderFieldKey(i); nzYFa J+
if(sHeader!=null) ~ C_2D?
{ wAb_fU&*
if(sHeader.equals("Content-Length")) '?fn} V
{ p|*b] 36
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;rF:$37^
break; oDA'}[/
} KRcg
} .fW`/BXE
else UgO\+cI
break; VxAR,a1+n
} p@znmn-
} ]@1ncn7N
catch(IOException e){e.printStackTrace ();} ]Otl(\v(h
catch(Exception e){e.printStackTrace ();} :TWHmxch
z!j`Qoh?V9
}W%}_UT
Utility.log(nFileLength); ]gj@r[
Ki@8
t!Av[K
return nFileLength; V'?nS&,i
} 1-gX=8]]
8i"{GGVC
{k~$\J?.
//保存下载信息（文件指针位置） 1r w>gR
private void write_nPos() eS Fmx
{ .g&BA15<F6
try{ 7y`~T+
output = new DataOutputStream(new FileOutputStream(tmpFile)); anV)$PT=
output.writeInt(nStartPos.length); A><%"9pZ
for(int i=0;i<nStartPos.length;i++) Qg oXOVo6
{ gf@'d.W}
// output.writeLong(nPos); EGMcU|yL
output.writeLong(fileSplitterFetch.nStartPos); )I}G:bBa
output.writeLong(fileSplitterFetch.nEndPos); h/w- &7t
} C,z]q$4
output.close(); cE]kI,Fw,M
} K|1^?#n
catch(IOException e){e.printStackTrace ();} mg;AcAS.o,
catch(Exception e){e.printStackTrace ();} @+!d@`w:z2
} ?x/L"h&Kp
},L[bDOV07
]V]o%onW
//读取保存的下载信息（文件指针位置） ?^+|V,<
private void read_nPos() '}Y8a$(;V
{ |Z/ySAFM
try{ p.IfJ|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nb!m>0*/
int nCount = input.readInt(); Z,&ywMm/G
nStartPos = new long[nCount]; )T+htD)
nEndPos = new long[nCount]; WL~`L!_. A
for(int i=0;i<nStartPos.length;i++) Q&\k"X1
{ *Ee# x!O
nStartPos = input.readLong(); Fy@D&j
nEndPos = input.readLong(); MLb\:Ihy
} n(+:l'#HJ
input.close(); >y@w-,1he
} $7*Ml)H!9
catch(IOException e){e.printStackTrace ();} &pAT
catch(Exception e){e.printStackTrace ();} ;g*6NzdA
} g<-cHF
Mf63 59
h 2zCX
private void processErrorCode(int nErrorCode) RinRQd
{ `F@yZ4L3S
System.err.println("Error Code : " + nErrorCode); $p@g#3X`
} nNKL{Hp
S'e2~-p0F
-d~'tti
//停止文件下载 Sq'z<}o
public void siteStop() 1XKk~G"D
{ ublY!Af
bStop = true; `xr%LsNn
for(int i=0;i<nStartPos.length;i++) +A3H#'
fileSplitterFetch.splitterStop(); tQ67XAb
v>5F[0gE
N@$%0!
} vX\e* v
} xd3
//负责部分文件的抓取 KPhqD5, (
**FileSplitterFetch.java GdU W$.
*/ 2 *$n?
package NetFox; L9@jmh*E
Ymu=G3-
-Me\nu8(RF
import java.io.*; AngwBZ@
import java.net.*; _;{-w%Vf
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public class FileSplitterFetch extends Thread { CmOb+:4@K
~}*;Ko\
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String sURL; //File URL fL;p^t u3
long nStartPos; //File Snippet Start Position (% P=#vZ
long nEndPos; //File Snippet End Position D,/9rH
int nThreadID; //Thread's ID 8.':pY'8"
boolean bDownOver = false; //Downing is over !*gAGt_
boolean bStop = false; //Stop identical 3D0I5LF&
FileAccessI fileAccessI = null; //File Access interface z sPuLn9G
p/~kw:I
$wTX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >lmL
{ 3)a29uc:U
this.sURL = sURL; kVv <tw
this.nStartPos = nStart; <*(R+to^d
this.nEndPos = nEnd; C5UDez
nThreadID = id; -;$/<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~*Qpv&y)
} bobkT|s^s
su;S)yZb
Y +54z/{
public void run() Y;Gm,
{ zP}v2
while(nStartPos < nEndPos && !bStop) 1,'^BgI,
{ +hgCk87%#
+=Wdn)T
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try{ :j<JZs>`R
URL url = new URL(sURL); T(^8ki
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t}*!UixE
httpConnection.setRequestProperty("User-Agent","NetFox"); a|uZJ*
String sProperty = "bytes="+nStartPos+"-"; bU`yymf{L
httpConnection.setRequestProperty("RANGE",sProperty); oH0F9*+W
Utility.log(sProperty); ^\jX5)2{
PSS/JFZ^
Gw^=kzh
InputStream input = httpConnection.getInputStream(); a&Du5(r;!
//logResponseHead(httpConnection); \'Kj.EO{?$
PM!t"[@&
v:1Vli.
byte[] b = new byte[1024]; a' o8n6i
int nRead; iGVb.=)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PJ:5Lb<
{ [(EH
nStartPos += fileAccessI.write(b,0,nRead); |o=ST
//if(nThreadID == 1) <|Eby!KXR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +\vY;!^
} -Bv1}xf=6
{0WIDD
=2]rA
Utility.log("Thread " + nThreadID + " is over!"); T)f_W
bDownOver = true; X3iRR{< @
//nPos = fileAccessI.write (b,0,nRead); 9~%]|_(
} 6@;L$QYY-V
catch(Exception e){e.printStackTrace ();} wf<`J/7u
} /M*\t.[ 46
} o\;"|O}
j{Jc6U
X3L[y\
//打印回应的头信息 3nC#$L-
public void logResponseHead(HttpURLConnection con) | 4oM+n;Y
{ !2U7gVt"*
for(int i=1;;i++) u+'@>%7
{ 5@t uo`k
String header=con.getHeaderFieldKey(i); wp*&&0O!
if(header!=null) (VPM>ndkw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #0<y0uJ(y
Utility.log(header+" : "+con.getHeaderField(header)); CSqb)\8Oi*
else FoD/Q
break; 1o~U+s_r
} mc=!X
} ,#jhKnk2e
[(hvK{)
d7tD|[(J
public void splitterStop() X)iWb(@k"7
{ NRuG?^/}d
bStop = true; &J/4J
} LXu"rfp
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*[1u[H9Cv
} 0B$7S,2
PVS<QN%
&Wz`>qYL*
/* fzFvfMAU
**FileAccess.java ks%7W -
*//文件访问(定位，写) +65~,e
package NetFox; bu"68A;>
import java.io.*; q4.dLU,1
)Rhff$
Ad`[Rt']kI
public class FileAccessI implements Serializable{ _[{:!?-?
[N95.aD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ? __aVQ7
RandomAccessFile oSavedFile; s{z~Axup-
long nPos; u_6BHsU
3gI[]4lRH
A M1C $
public FileAccessI() throws IOException 3b?OW7H
{ O{B e )E~
this("",0); eb.cq"C
} g<rKV+$6
>: W-C{%
CmJ?_>
public FileAccessI(String sName,long nPos) throws IOException ;la#Vf:]
{ 7dlKdKH
oSavedFile = new RandomAccessFile(sName,"rw"); ra9cD"/J &
this.nPos = nPos; $['7vcB^
oSavedFile.seek(nPos); &weY8\HD
} L*UV
S}m$,<x
%7NsBR!y
public synchronized int write(byte[] b,int nStart,int nLen) ^)hAVf~E
{ dDqr B-G
int n = -1; >St.&#c
try{ 4{*tn"y
oSavedFile.write(b,nStart,nLen); &PRx,G5
n = nLen; Y3P.|
} up3?$hUc.
catch(IOException e) q?imE~&U
{ FI1THzW4J
e.printStackTrace (); %qS]NC
} + %MO7vL
XDpfpJ,z"}
mfeMmKFu\
return n; e~+(7_2
} +9CEC1-l
A$%Q4jC}
$N}/1R^?r
} * MSBjH|
E\]OySC%C$
G}!7tU
/* lX98"}
**SiteInfoBean.java & Fg|%,fv]
*/ %6NO0 F^
package NetFox; JkSdLj
$^W-Wmsz
V&Xi> X8
public class SiteInfoBean { Fw_ (q!
Yz&*PPx
r-RCe3%g%
private String sSiteURL; //Site's URL 1Yc%0L(
private String sFilePath; //Saved File's Path ?xtt7*'D
private String sFileName; //Saved File's Name "El^38Ho
private int nSplitter; //Count of Splited Downloading File Xw7{R
pOqGAD{D$
rQ9*J
public SiteInfoBean() iD>G!\&
{//nSplitter的缺省值为5 2.[_t/T
//default value of nSplitter is 5 _Ry_K3K
this("","","",5); aB6Ye/Io
} F,*2#:Ki
I3Lg?bZ
H4M{_2DO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ETU-]R3
{ %x&F4U
sSiteURL= sURL; 2HcsQ*H]G
sFilePath = sPath; j((hqJr
sFileName = sName; IE&_!ce
this.nSplitter = nSpiltter; ZhH+D`9
{mNdL J
]EB6+x!G
} ]]>nbgGn#
!G7h9CF|{
O$a#2p&
public String getSSiteURL() >&bv\R/
{ ($c`s8mp
return sSiteURL; 5^\m`gS
} x+4vss
|5W8Q|>%
]Z_$'?f
public void setSSiteURL(String value) +H7y/#e+3
{ K} +S+ *_
sSiteURL = value; "X`RQ6~]>
} F&xv z2G
[M4xZHd#o
g;8M<`qvf
public String getSFilePath() ASR-a't6
{ !~WZ_z
return sFilePath; &`\ep9
} 1YFeVMc
]GNh)
ei@3,{~5
public void setSFilePath(String value) TZ'aNcGg
{ [a@B =E
sFilePath = value; H.:9:I[n
} aVP5%
QO2Ut!Y
TFO74^
public String getSFileName() S/VA~,KCe;
{ QP:9%f>=
return sFileName; \*uugw,\y
} y`rL=N#
pajy#0 U
UxeL cUP
public void setSFileName(String value) k52QaMKa~A
{ 4f!dYo4L
sFileName = value; >Fyu@u
} hfg O
;}D-:J-z_
pw3(t
public int getNSplitter() uN9e:;
{ x9%-plP
return nSplitter; q[P~L`h S
} t@)my[!
x6ahZ
&$F[/[Ds+
public void setNSplitter(int nCount) dKm`14f]@G
{ KzG_ <<
nSplitter = nCount; ]YsR E>
} $T),DUYO
} 9 ZGV%Tw
tq&Yek>C
EjSD4
/* r1G8]agO
**Utility.java A#35]V06
*/ MtUY?O.P2
package NetFox; D#jX6
Sph*1c(R
ufPCx|x~
public class Utility { dF e4K"
| 3giZ{
DWrbp
public Utility() +9zA^0
{ g\&2s,
BFh$.+D
\f"1}f
} *H"aOT^{
6vobta^w
//线程睡眠 _CE9B e\
public static void sleep(int nSecond) -!TcQzHUs
{ h<Wg3o
try{ AS|Rd+.
Thread.sleep(nSecond); io2@}xZF
} U5<@<j(@
catch(Exception e) 6m[9b*s7
{ wyw<jH
e.printStackTrace (); g$w6kz_[
} El (/em
} Z`s!dV]e9
,|pp67
//日志 {eR9 ;2!
public static void log(String sMsg) oZ:{@=
{ v[&'k\
System.err.println(sMsg); fHfY}BQS
} "8HE^Po/pn
tpYa?ZCM
8lwM{?k$
public static void log(int sMsg) sRq U]i8l
{ G{o+R]Us
System.err.println(sMsg); w>vH8f
} Qra>}e%*
} "={L+di:M
*jF#^=
*Jt8
/* ]XUSqai
**TestMethod.java Mr*|9h
*/ yvxl_*Ds8
package NetFox; _tj&Psp
% {Q-8w!
D{C:d\ e)$
public class TestMethod { }-p,iTm
yd>}wHt
7Fl-(Nv`
public TestMethod() C3S`}o.
{ ///xx/weblogic60b2_win.exe O&'/J8
try{ ow.j+<M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `o si"o9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4*M@]J "
SiteFileFetch fileFetch = new SiteFileFetch(bean); z+39ee
fileFetch.start(); I7mG/
} M<[?g5=#
catch(Exception e){e.printStackTrace ();} n93zD*;5
(X}@^]lpa
<v$QM;Ff
} A1A3~9HuK
cOku1g8
<LA^%2jT
public static void main(String[] args) Q)^g3J
{ FFe)e>bH
new TestMethod(); &qRJceT(
} Jps .;yjk
} @ls.&BHUP
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