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)); $H+X'1
} _k]R6V:
for(int i=0;i<nEndPos.length-1;i++) -Wa<}Tz
{ CP\[9#]:
nEndPos = nStartPos[i+1]; YZfi-35@g
} =SmU;t>t/
nEndPos[nEndPos.length-1] = nFileLength; F#|y,<}<
} kO}%Y?9d
} <k8WnA ~Fl
T+T)~!{%
M 0}r)@
//启动子线程 dCM&Yf}K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]R\L~Kr
for(int i=0;i<nStartPos.length;i++) mRAt5a#is
{ k(RKAFjY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;R0LJApey
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B ZU@W%E
nStartPos,nEndPos,i); W3[>IH"+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {f/]K GGk
fileSplitterFetch.start(); %1p-DX6
} <m\Y$Wv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .BJoY <P*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3(K.:376
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (L4llZ;q
nEndPos = " + nFileLength); Vp; `!+z"
// fileSplitterFetch[nPos.length-1].start(); ;5;>f)diS
1.@{5f3T
Eg1TF oIWl
//等待子线程结束 9j^rFG!n
//int count = 0; CC^]Y.9
//是否结束while循环 9LPXhxNwB
boolean breakWhile = false; >y8>OJ?A7-
&iu]M=Yb
>k\p%{P
while(!bStop) }ACg#;>/+
{ X,+a 6F
write_nPos(); FWeUZI+
Utility.sleep(500); ~m<K5K6 V
breakWhile = true; Da)p%E>Q
,k_ b-/
<v9IK$J
for(int i=0;i<nStartPos.length;i++) ~*3Si(4l/
{ JtSwbdN
if(!fileSplitterFetch.bDownOver) W2-l_{
{ A?04,l]y
breakWhile = false; G)YmaHeI;[
break; - s'W^(
} pvl];w
} eXsp0!v
if(breakWhile) E8PwA.
break; *MfH\X379
'wFhfZB1!B
-ewR:Y@j
//count++; ]6^S:K_"
//if(count>4) CB9:53zK9
// siteStop(); #\N8E-d
} %x,HQNRDU
/Bgqf,N |
?IQDk|<%
System.err.println("文件下载结束！"); oMYFfnoAa
} &Oz
catch(Exception e){e.printStackTrace ();} 3%r/w7Fc
} @Oz3A<M
P=}dR&gk'
n&&C(#mBC
//获得文件长度 :Nf(:D8
public long getFileSize() Jm)7!W%3
{ z7BFkZ6+
int nFileLength = -1; C8v
try{ ^& *;]S`
URL url = new URL(siteInfoBean.getSSiteURL()); *GYLj[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a5m[ N'kah
httpConnection.setRequestProperty("User-Agent","NetFox"); MV3K'<Y
#]^C(qmb:
~G8l1dD
int responseCode=httpConnection.getResponseCode(); wbr$w>n
if(responseCode>=400) V%;dTCq
{ 6&<QjO
processErrorCode(responseCode); ,_V/W'
return -2; //-2 represent access is error z@ZI$.w
} Q;l%@)m+~
?z|Bf@TJ[+
x ]}'H
String sHeader; I m-M2n
,>qtnwvlHP
L Y4bn)Qf
for(int i=1;;i++) tUJe-3,
{ R-W.$-rF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r/':^Ex
//Utility.log(in.readLine()); ,hJx3g5#n
sHeader=httpConnection.getHeaderFieldKey(i); BE&8E\w
if(sHeader!=null) *1-0s*T
{ JgHYuLB
if(sHeader.equals("Content-Length")) dg*xo9Xi`
{ 6NyUGGRq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F5H*z\/={
break; NMg(tmh
} nfZe"|d
} 3rZPVR$))
else [vuikJP>1k
break; im+g|9@%
} H/ ejO_{
} }jce5E
catch(IOException e){e.printStackTrace ();} !Q_Kil.9
catch(Exception e){e.printStackTrace ();} RWu< dY#ym
$L|+Z>x
w AdaP9h
Utility.log(nFileLength); Z= -fL
p|qLr9\A
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return nFileLength; -;8a* F
} OhaoLmA}6
opn6 C )
Jk`l{N
//保存下载信息（文件指针位置） "g"%7jK
private void write_nPos() i&m6;>?`
{ !.iFU+?V
try{ 3qu?qD
output = new DataOutputStream(new FileOutputStream(tmpFile)); ">8oF.A^
output.writeInt(nStartPos.length); Z/GSR$@lI
for(int i=0;i<nStartPos.length;i++) :qR8 e J
{ dR>$vbjh1Z
// output.writeLong(nPos); |FaK=e
output.writeLong(fileSplitterFetch.nStartPos); j5n"LC+oz
output.writeLong(fileSplitterFetch.nEndPos); s)3CosU
} 2|1CGHj\
output.close(); `B8`<3k/(
} D8B\F5..c#
catch(IOException e){e.printStackTrace ();} 6W]C`
catch(Exception e){e.printStackTrace ();} v^t oe
} /18fpH|
2RqV\Jik
;sUvY*Bcm
//读取保存的下载信息（文件指针位置） cw0@Z0
private void read_nPos() tqB6:p-%
{ /IX555/dR1
try{ (?7}\B\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -y_q
int nCount = input.readInt(); L`Ys`7
nStartPos = new long[nCount]; Hi\z-P-
nEndPos = new long[nCount]; c":2<:D&
for(int i=0;i<nStartPos.length;i++) #U3q +d+^
{ RZqMpW
nStartPos = input.readLong(); Xa"I
nEndPos = input.readLong(); )VG>6x
} _~>WAm<
input.close(); }a UQ#x
} 6&LmR75C
catch(IOException e){e.printStackTrace ();} XdlA)0S)
catch(Exception e){e.printStackTrace ();} +g1+,?cU
} >#T?]5Z'MF
(bNoe(<qU
8OS^3JS3"
private void processErrorCode(int nErrorCode) ]H`pM9rC
{ qM Qu!%o
System.err.println("Error Code : " + nErrorCode); "~Kph0-
} >wYmx4W>
ns/*WH&[x
V=>]&95-f
//停止文件下载 *cXi*7|=
public void siteStop() K-c>J uv&,
{ l8%BRG
bStop = true; Y>2#9LA
for(int i=0;i<nStartPos.length;i++) \SgBI/L^
fileSplitterFetch.splitterStop(); BP&]t1p
J*%IvRg
3F6A.Ny
} d[H`Fe6h
} RA+M.
//负责部分文件的抓取 X}QcXc.d
**FileSplitterFetch.java x FvKjO)
*/ dgByl-8Q
package NetFox; 8{&.[SC7
r M}o)
|w>b0aY
import java.io.*; CNWA!1n^Hy
import java.net.*; "N,@J-]/k
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o=lZl_5/u;
public class FileSplitterFetch extends Thread { HB<>x
+n &8" )
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String sURL; //File URL 5VVU%STP
long nStartPos; //File Snippet Start Position >B$ IrM7J
long nEndPos; //File Snippet End Position lEQj62zIQ
int nThreadID; //Thread's ID 'w/S6j
boolean bDownOver = false; //Downing is over Oq}7q!H
boolean bStop = false; //Stop identical vMJ_n=Vf
FileAccessI fileAccessI = null; //File Access interface c4Q%MRR
X VH(zJ
FId,/la
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VYH $em6
{ :yw(Co]f
this.sURL = sURL; -0k{O@l"
this.nStartPos = nStart; ^`$-c9M?'
this.nEndPos = nEnd; C(xsMO'k,,
nThreadID = id; y<BG-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xoq -
} ;<F^&/a|yQ
$p}q,f.
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public void run() }1a(*s,s-^
{ G8Ow;:Ro
while(nStartPos < nEndPos && !bStop) ':=20V
{ m.5@qmQ
[*H h6
g\49[U}[~F
try{ /p}pdXS
URL url = new URL(sURL); Y$ KR\ m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l['ER$(7
httpConnection.setRequestProperty("User-Agent","NetFox"); OSh'b$Z
String sProperty = "bytes="+nStartPos+"-"; v>j<ky
httpConnection.setRequestProperty("RANGE",sProperty); 0@ vzQ$
Utility.log(sProperty); !bX
tI.ho
|*8X80<
InputStream input = httpConnection.getInputStream(); u&f|z9
//logResponseHead(httpConnection); ( ~JtKSq%
XE;'K`%
[xdVuL;N
byte[] b = new byte[1024]; SK@lr
int nRead; }n,LvA@[0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1:{+{Yl7
{ ZlQ&m
nStartPos += fileAccessI.write(b,0,nRead); + =U9<8
//if(nThreadID == 1) ,o3`O|PiK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aCfWbJ@qiG
} k~QmDq
A'n7u'6=
G2=dq
Utility.log("Thread " + nThreadID + " is over!"); 4~d:@Gmk&
bDownOver = true; `0u)/s$
//nPos = fileAccessI.write (b,0,nRead); 530Kk<%^}8
} =,s5>2
catch(Exception e){e.printStackTrace ();} T7?z0DKi
} 5m>f1`4JS
} t<^7s9r;I
a\p`J9Z@
vhU#<59a1
//打印回应的头信息 1 a%1C`d
public void logResponseHead(HttpURLConnection con) #A< |qd
{ !H9zd\wc
for(int i=1;;i++) R0q|{5S
{ DKNcp8<J
String header=con.getHeaderFieldKey(i); #)%X0%9.*<
if(header!=null) &5%~Qw..
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +N|t:8qaf
Utility.log(header+" : "+con.getHeaderField(header)); ndvt $*
else AFsYP/g]
break; MJn=
} NMN&mJsmh
} 2Fbg"de3-
~KxK+6[ :
9G[t &r
public void splitterStop() w)>/fG|;
{ $WQm"WAKe
bStop = true; HoZsDs.XZ
} x*:"G'zT
u*T#? W?
8;3I:z&muQ
} :4Y5
R{9G$b1Due
?:7$c
/* OHH\sA
**FileAccess.java Ma ]*Pled
*//文件访问(定位，写) YgQb(umK
package NetFox; y@ c[S;
import java.io.*; tR?)C=4,
Ai`0Ud,M@
hdbm8C3
public class FileAccessI implements Serializable{ Ed#Hilk'
VF~kjH2>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xr^fP~V|)0
RandomAccessFile oSavedFile; Ye/Y<Ij
long nPos; %(r.`I$
h9&0"LHr
A%EGu4
public FileAccessI() throws IOException ;a(7%
{ AaM~B`B
this("",0); 1f$1~5Z
} X9YbTN
;jmT5XzL
#*"I?B/fd8
public FileAccessI(String sName,long nPos) throws IOException 8HWEObRY
{ K/!>[d
oSavedFile = new RandomAccessFile(sName,"rw"); 2:1 kSR^Ky
this.nPos = nPos; A-u}&}l<
oSavedFile.seek(nPos); 8?hj}}H
} $N4i)>&T2
cM=_i{c
M1K[6V!
public synchronized int write(byte[] b,int nStart,int nLen) =BeJ.8$@VC
{ 6PLdzZ{
int n = -1; 6+SaO !lR
try{ g:&PjKA
oSavedFile.write(b,nStart,nLen); Gr~J-#a3~D
n = nLen; n?v$C:jLN
} }Gd^r
catch(IOException e) rxeOT# N}
{ uAV-wc
e.printStackTrace (); bKr73S9
} 0E^S!A7
|_16IEJ
dF+:9iiAm
return n; "iuNYM5P
} v2vtkYQN
4`:Eiik&p
#D%l;Ae
} ^B(:Hv}G(:
Z07SK 'U
(usPAslr
/* LP}'upv
**SiteInfoBean.java ({hW
*/ Ka8Bed3
package NetFox; 9gETWz(3I
A3Vj3em
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public class SiteInfoBean { JzkI!5c<j
nO8e'&|
{fn1sGA
private String sSiteURL; //Site's URL N. 0~4H %U
private String sFilePath; //Saved File's Path `M ~-(,++
private String sFileName; //Saved File's Name 9Hs5uBe
private int nSplitter; //Count of Splited Downloading File dMa6hI{k
3/CKy##r%]
7"Q;Yi2(
public SiteInfoBean() b5l;bXp]
{//nSplitter的缺省值为5 <1kK@m -E
//default value of nSplitter is 5 I=7 YAm[W
this("","","",5); 35~1$uRA
} 28lor&Cc
#!w7E,UBi
v3r<kNW_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X>Y>1fI.
{ ov|pXi<e
sSiteURL= sURL; WCg&*
sFilePath = sPath; knRs{1}Pw{
sFileName = sName; {BD G;e
this.nSplitter = nSpiltter; x,QXOh\a
Jy-V\.N>s
8LGNV&Edg
} OJ<V<=MYZ
l'Uj"9r,
{\n?IGP?wd
public String getSSiteURL() uiaZ@
{ P:m6:F@hO
return sSiteURL; N[sJ5oF
} Rrp-SR?O
A7zL\U4
]U.*KkQ
public void setSSiteURL(String value) 1m<8M[6u
{ JQA]O/|N
sSiteURL = value; P u,JR
} +?GsIp@>jh
rpv<'$6
byX)4&
public String getSFilePath() e0`5PVJ
{ Vv*](iM
return sFilePath; Gg5+Ap D
} > |(L3UA9
@gjA8mL
e^orqw/I
public void setSFilePath(String value) oN=>U"<\1
{ bA/'IF+
sFilePath = value; Z4D[nPm$
} X=%e'P*X
t+A9nvj)
B[;aNyd<
public String getSFileName() 6rN.)dL.#N
{ [(Ihue
return sFileName; ?l^NKbw
} *Jg&:(#}<J
(vwKC D&
'_FxxLAO
public void setSFileName(String value) r|Q/:UV?w
{ 1krSX2L
sFileName = value; e}TDo`q
} T}Ve:S
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ria.MCe\!
public int getNSplitter() WO[O0!X
{ Nt7z ]F`
return nSplitter; @ [%K D
} 6-f-/$B
,7SqRY,+
:rEZR`
public void setNSplitter(int nCount) #E4|@}30`
{ PgYIQpV
nSplitter = nCount; &|fWtl;43
} 'oF('uR
} *)s^+F 0
]+T$D
QQ./!
/* f;obK~b[
**Utility.java "$A5:1;
*/ o8N,mGj}
package NetFox; x,TnYqT^
Y {|is2M9'
_tpOVw4I
public class Utility { Gk:k px
3|4<SMm
?7A>|p?"
public Utility() H}gp`YW:4
{ <AU0ir
b8|<O:]Hp
YhL^kM@c
} /?u]Fj
-{NP3zy
//线程睡眠 %\Mc6
public static void sleep(int nSecond) yBfX4aH:`
{ $ U-#woXa
try{ 5'n$aFqI
Thread.sleep(nSecond); VI?kbqjo
} "&@{f:+
catch(Exception e) K<MWiB&
{ =LKf.@]#
e.printStackTrace (); >FqU=Q
} B{>x
} 4++pK;I
=-/sB>-C
//日志 ;3+_aoY
public static void log(String sMsg) @x_0AkZU
{ gpogv -
System.err.println(sMsg); c"/Hv
} a7jE*%f9
,6SzW+L7
Ht|"91ZC5
public static void log(int sMsg) :}-izd)/j
{ C~T*Wlk
System.err.println(sMsg); ff 6x4t
} 3)hQT-)
} 3 5/ s\
4mnVXKt%.
^;wz+u4^l
/* 1wBmDEhS
**TestMethod.java ym'!f|9AA
*/ Wjr^: d
package NetFox; Av!xI
|v_ttJ;+Y
LR3>_t
public class TestMethod { q2*1Gn9!j
$J#Z`%B^y
,@\z{}~v
public TestMethod() e<+b?@}=B
{ ///xx/weblogic60b2_win.exe -?NAA]P5c@
try{ \s7/`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5-UrHbpCZ#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kc<5wY_t
SiteFileFetch fileFetch = new SiteFileFetch(bean); lLLPvW[Q
fileFetch.start(); WG +]
} ~bz$]o-<
catch(Exception e){e.printStackTrace ();} 9K-,#a
uobQS!
vb3hDy
} 8WC_CAP
svtqX-Vj"
?%$~Bb _
public static void main(String[] args) yYdh+x
{ FT!Xr
new TestMethod(); 0 gR_1~3
} S}qGf%
} rA}mp]
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