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)); :f/T$fa*
} SZ&I4-
for(int i=0;i<nEndPos.length-1;i++) %FhUjHm
{ "G[yV>pxv
nEndPos = nStartPos[i+1]; Bs!F |x(
} qk *b,`;
nEndPos[nEndPos.length-1] = nFileLength; |b+ZKRW
} >* )fmfY
} %S$+3q%F
b;5&V_
I"hlLP
//启动子线程 J/(^Z?/~P!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t9\}!{<s
for(int i=0;i<nStartPos.length;i++) +I>V9%%vW_
{ E|K|AdL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Q!#v{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Yf?hl
nStartPos,nEndPos,i); &*YFK/]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >oGs0mej
fileSplitterFetch.start(); TCLXO0
} \5pBK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U^&,xz$Cg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m5_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !zZ3F|+HB
nEndPos = " + nFileLength); crbph.0
// fileSplitterFetch[nPos.length-1].start(); hqW),^\>'
g@2f&m
t8ZzBD!dP
//等待子线程结束 xh:A*ZI=7
//int count = 0; !Pc&Sg
//是否结束while循环 /_[?i"GW
boolean breakWhile = false; pdySip<
V]5MIiNl
R KXhD PA
while(!bStop) 0CpE,gg
{ WS6;ad;|
write_nPos(); ^:u-wr8?{
Utility.sleep(500); Ial"nV0>0
breakWhile = true; I&wJK'GM`
,.z?=]'en
)qua0'y]@
for(int i=0;i<nStartPos.length;i++) i?:#lbw_
{ 7ND4Booul
if(!fileSplitterFetch.bDownOver) v];P| Fi
{ k!"6mo@rd
breakWhile = false; yXT.]%)
break; 5q;c=oRUj
} .x'?&7#(
} hYbaVE
if(breakWhile) .G-L/*&%
break; @+7CfvM
pCC3r t(
GMlJM
//count++; )W/_2Q.
//if(count>4) &Lbh?C
// siteStop(); hplxs#
} OK(xG3T
&,tj.?NCn
6F_:,b^
System.err.println("文件下载结束！"); pnTz.)'46
} O$7cN\Z
catch(Exception e){e.printStackTrace ();} .#}A/V.-Y
} @:}la
*RmD%[f
Zg9VkL6Z6
//获得文件长度 ^fj30gw7\5
public long getFileSize() >mj WC) U
{ i1 c[Gk.o
int nFileLength = -1; &ZL4/e
try{ /*(&Dmt>
URL url = new URL(siteInfoBean.getSSiteURL()); kkIG{Bw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >avkiT2
httpConnection.setRequestProperty("User-Agent","NetFox"); \olY)b[
8~sC$sIlE
_:>t$* _
int responseCode=httpConnection.getResponseCode(); X!6$<8+1OV
if(responseCode>=400) )"J1ET,z
{ _BoA&Ism
processErrorCode(responseCode); n}C0gt-
return -2; //-2 represent access is error WidLUv
} 1'H!S%fS
n5y0$S/D
%I;uqf
String sHeader; t$b5,"G1
vDyGxU!#\
)"](?V
for(int i=1;;i++) Z= =c3~
{ ;(rK^*`fO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :`c@&WF8
//Utility.log(in.readLine()); .hjN*4RY
sHeader=httpConnection.getHeaderFieldKey(i); eH~T PH
if(sHeader!=null) n(.L=VuXn
{ Rq`5ff3,
if(sHeader.equals("Content-Length")) (+}44Ldt
{ `~D{]'j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yH9&HFDp
break; owwWm1@
} gYloY=.Z$'
} 'wWuR@e#&
else .EC~o
break; q{+}0!o
} yyGn<
} LP/SblE
catch(IOException e){e.printStackTrace ();} iba8G]2
catch(Exception e){e.printStackTrace ();} x`I"%pG
0U !&|i\
6!8uZ>u%Vg
Utility.log(nFileLength); t#%J=zF{
J ~KygQ3%
T-]UAN"O
return nFileLength; 79I"F'
} AmQsay#I_
%/BBl$~ji
N4b{^JkF
//保存下载信息（文件指针位置） KUC%Da3
private void write_nPos() CAmIwAx6;
{ q\<NW%KtX
try{ 2`> (LH
output = new DataOutputStream(new FileOutputStream(tmpFile)); _#uRKy<`N
output.writeInt(nStartPos.length); BU7QK_zT:
for(int i=0;i<nStartPos.length;i++) shO4>Ha
{ (j(9'DjP
// output.writeLong(nPos); ]:m4~0^#-(
output.writeLong(fileSplitterFetch.nStartPos); fAfB.|cd
output.writeLong(fileSplitterFetch.nEndPos); tgHN\@yj
} F~~9/#
output.close(); @1U6sQ
} qQ1D}c@
catch(IOException e){e.printStackTrace ();} @, AB2D
catch(Exception e){e.printStackTrace ();} ~M1T @Mv
} g|h;*
,Ek6X)|@
y<#Hq1
//读取保存的下载信息（文件指针位置） +UX} "m~W
private void read_nPos() ylDfr){
{ (cI@#x
try{ E^m)&.+'M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]\]mwvLT
int nCount = input.readInt(); _@VKWU$$
nStartPos = new long[nCount]; Xn5LrLM&
nEndPos = new long[nCount]; #a'CoJs
for(int i=0;i<nStartPos.length;i++) *Wcq'S
{ dj}P|v/;z
nStartPos = input.readLong(); Z=<D`
nEndPos = input.readLong(); ldc`Y/:{
} '#~Sb8
input.close(); 8%xiHPVg
} =/\l=*
catch(IOException e){e.printStackTrace ();} QUF1_Sa
catch(Exception e){e.printStackTrace ();} Zm(}~C29
} iR8;^C.aT
m`b:#z
ej&o,gX
private void processErrorCode(int nErrorCode) = N:5#A
{ L Z3=K`gj
System.err.println("Error Code : " + nErrorCode); U.<ad
} n@S|^cH
zE7)4!
GkKoc v
//停止文件下载 e'=#G$S?g
public void siteStop() 5RYrAzQo
{ -Byl~n3*D
bStop = true; v{8r46Y~Z)
for(int i=0;i<nStartPos.length;i++) APU~y5vG (
fileSplitterFetch.splitterStop(); LrV|Y~
jtqU`|FSQ
lg 1r]
} n.o_._mu2
} x7xQrjE
//负责部分文件的抓取 aDE}'d1qo
**FileSplitterFetch.java I#W J";kqB
*/ '2{60t_A
package NetFox; C4|79UG>s
!{ORFd
T\Jm=+]c!
import java.io.*; &*~_ "WyU
import java.net.*; ZZ>(o d!B
#O7phjzgD
4c.!^EiV
public class FileSplitterFetch extends Thread { |lVi* 4za%
;|oem\dKv
F_V/&OV
String sURL; //File URL mf2Qu
long nStartPos; //File Snippet Start Position 4>]B8ZxH
long nEndPos; //File Snippet End Position 6h\; U5
int nThreadID; //Thread's ID (T",6xBSG
boolean bDownOver = false; //Downing is over x0xQFlGk
boolean bStop = false; //Stop identical yeV|j\TJI.
FileAccessI fileAccessI = null; //File Access interface j 2e|
%O>_$ 4q
jf& oN]sZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s6I/%R3
{ N$cAX^~
this.sURL = sURL; ?C_Y2JY
this.nStartPos = nStart; +^%0/0e
this.nEndPos = nEnd; :n oZ p:a
nThreadID = id; d*:J0J(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _No<fz8
} @DyMq3Gt?&
-nB. .q
%v]-:5g'|
public void run() 4o( Q+6m
{ qn` \g
while(nStartPos < nEndPos && !bStop) ~|`jIqU
{ 1( ]{tF
!GoHCe[10
;oRgg'k<
try{ /qXP\ a
URL url = new URL(sURL); .+-7 'ux
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7*47mJyc
httpConnection.setRequestProperty("User-Agent","NetFox"); ,f[Oy:fr
String sProperty = "bytes="+nStartPos+"-"; 05;J7T<
httpConnection.setRequestProperty("RANGE",sProperty); K)9f\1\
Utility.log(sProperty); 0JLQ.%_
.c_qMTm"
_;G|3>5u
InputStream input = httpConnection.getInputStream(); {uiL91j.
//logResponseHead(httpConnection); C0j`H(
*0%G`Q
VqdR
byte[] b = new byte[1024]; D}bCMN<
int nRead; $eh>.c'&]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E^V4O l<
{ :"Kr-Hm`
nStartPos += fileAccessI.write(b,0,nRead); 1zY"Uxp
//if(nThreadID == 1) k)S'@>n{u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U p: M[S
} h=ko_/<
CNyV6jb
?rgtbiSW-
Utility.log("Thread " + nThreadID + " is over!"); \v([,tiW%
bDownOver = true; f15n ~d
//nPos = fileAccessI.write (b,0,nRead); p}-B>v
} Y/G~P,9
catch(Exception e){e.printStackTrace ();} F2mW<REg{
} g}*F"k4j
} "A&HNkRz
KoTQc0b!
u/X1v-2
//打印回应的头信息 -{S:sK.o
public void logResponseHead(HttpURLConnection con) LT)G"U~
{ |j7{zsH
for(int i=1;;i++) A$o?_
{ *`bAu *
String header=con.getHeaderFieldKey(i); N(L?F):fT
if(header!=null) !"N-To-c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _.3O(?p,
Utility.log(header+" : "+con.getHeaderField(header)); b)@b63P_
else {~eVZVv
break; %jmL#IN)
} Py-}tFr
} @wOX</_g
.'^Pg
;Fm7!@u^0
public void splitterStop() E=8$*YUW(g
{ nn6&`$(Q~
bStop = true; B&c*KaK;~
} ,.&y-?
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/|2 hW`G
} 8iwqy0<
JO"-"&>
rP7f~"L
/* mA>u6Rlc
**FileAccess.java ;]xJC j
*//文件访问(定位，写) #&ZwQw
package NetFox; V.Ki$0>
import java.io.*; E]j2%}6Z%
8\@&~&(y:
/4PV<[ :_
public class FileAccessI implements Serializable{ 86N"EuH$
Erd)P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 maR5hgWCHe
RandomAccessFile oSavedFile; UuvI?D
long nPos; sX$EdIq
aL%amL6CX
0755;26Bx
public FileAccessI() throws IOException ^+20e3 ~Y
{ z}:|is)?
this("",0); L#^'9v}Hb
} jk'.Gz
t^zmvPDK
ypK1 sw
public FileAccessI(String sName,long nPos) throws IOException \E3evU
{ }^np
oSavedFile = new RandomAccessFile(sName,"rw"); =Vm"2g,aA
this.nPos = nPos; {Ex*8sU%p%
oSavedFile.seek(nPos); ni$S@0
} -$js5Gx1
&hb:~>
5s'oVO*hW
public synchronized int write(byte[] b,int nStart,int nLen) 7jL3mI;n%;
{ /X_g[*]?
int n = -1; vS{zLXg
try{ <cn{S`
oSavedFile.write(b,nStart,nLen); E8=8OX/{Y
n = nLen; ,>rr|O
} 5}uH;E)4
catch(IOException e) 6.!Cm$l
{ =E?!!EIq.
e.printStackTrace (); 8;C_@
} :DlgNR`bq
}yfSF|\
dMnJ)R
return n; g5 J[ut
} _*SA_.0
{{WA=\N8C
1b,,uI_
} e /4{pe+,
eKq`t.*Ft
'F- wC!
/* ^" EsBt
**SiteInfoBean.java ^\z.E?v%
*/ mrzrQ@sN
package NetFox; #=G[~m\
x!A.**
oP$l(k
public class SiteInfoBean { 4\.1phe$a
f"=1_*eH
-xc*R%k
private String sSiteURL; //Site's URL $:#{Y;d
private String sFilePath; //Saved File's Path B~o;,}
private String sFileName; //Saved File's Name >0W:snNK
private int nSplitter; //Count of Splited Downloading File 8e`'Ox_5a
b0A*zQA_)
I?l%RdGW
public SiteInfoBean() L|7F%oR
{//nSplitter的缺省值为5 [84f[`!Ui
//default value of nSplitter is 5 )jh4HMvmC
this("","","",5); SA| AS<
} 1kG{z;9
_k0X)N+li
\a|FhhI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ],lrT0_cT
{ y&HfF~
sSiteURL= sURL; L"w% ew
sFilePath = sPath; s)=fs#%
sFileName = sName; jIq@@8@o
this.nSplitter = nSpiltter; "Dc6kn^}3
7fVlA"x
DriJn`vtzq
} G8w<^z>pTg
&i&k 4
|mSFa8G@
public String getSSiteURL() %Ts6M,Fpp
{ )%4%Uo_Xm
return sSiteURL; 2;Ij~~
} 1}moT#
t:DZow
}tvLe3O
public void setSSiteURL(String value) )575JY `6K
{ )T-C/ 3
sSiteURL = value; PdUlwT?8C
} #1INOR9
MZyzc{c,
4z^ ?3@:K
public String getSFilePath() 2S~cW./#fX
{ #J1vN]g
return sFilePath; Uxla,CCp-
} $\S;f"IM.
[Yo3=(7J
tE i-0J
public void setSFilePath(String value) q5jLK)
{ K%Dksx7ow
sFilePath = value; B0_[bQoc1
} RTPxAp+\5
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y\=(;]S'
public String getSFileName() 0q|.]:][Eo
{ AS 5\X.%L*
return sFileName; aR3R,6ec
} ^ :%"Z&
9ANC,+0p
8<,b5
public void setSFileName(String value) dQ&S&SW
{ L*;XjacI]
sFileName = value; ]2^tV.^S^
} h/I'9&J>*
:lF[k`S T
9}~WwmC|x
public int getNSplitter() $D`~X`
{ cY%[UK$l
return nSplitter; aBo8?VV]8
} X bF;
1b4aY> Z
4)'8fi
public void setNSplitter(int nCount) G~,K$z/-l
{ HPc7Vo(
nSplitter = nCount; WM& k
} I\NiA>c
} %+PWcCmn
:K%{?y
d3A= (/>D
/* qT`sPEs;V
**Utility.java ]dZ8]I<$C
*/ ztSP4lW
package NetFox; m$T?~oo
<E2+P,Lgw
71AR)6<R
public class Utility { g.AMCM?z
j@4 yRl ^
SU0K#:
public Utility() Kjbz\~
{ v 4@=>L
13oR-Stj|
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} /O"IA4O
EJ$-
//线程睡眠 ^;J@]&[ ~
public static void sleep(int nSecond) GA19=gow
{ gu+c7qe
try{ ahagt9[,:F
Thread.sleep(nSecond); zd)2@jX=
} l3Vw?f
catch(Exception e) Vp =
{ "=l<%em
e.printStackTrace (); i ! wzID
} I(6k.PQ
} D]+0X8@kH7
__U;fH{c
//日志 U#oe8(?#
public static void log(String sMsg) */gm! :Ym
{ {^TVZdw
System.err.println(sMsg); ]h0Fv-[A
} rbP" n)0=
([loWr}QR
5oz[Njq4
public static void log(int sMsg) :tP:X+?O
{ pdnkHR$
System.err.println(sMsg); ny:c&XS
} i2or/(u`
} K*uFqdLL!
8i!~w 7z
hJ8|KPgdw
/* F(E3U'G
**TestMethod.java <UJgl{-
*/ l6b3i v,
package NetFox; '>:mEXK}w
-a`EL]NX
Lu&2^USTO
public class TestMethod { }Sa2s&[<
J-g#zs
k[oU}~*U+
public TestMethod() Y$3H$F.+
{ ///xx/weblogic60b2_win.exe @F_#d)+%>
try{ % R~9qO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4kO[|~#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q_Td!?2?
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;$W/le"Xr
fileFetch.start(); jRXpEiM
} 84[T!cDk
catch(Exception e){e.printStackTrace ();} 'tK5s>gv<
_%Ay\4H^\
-d\O{{%>.z
} =Haqr*PDx
B\&;eZY'G
;i`X&[y;
public static void main(String[] args) .?b2Bd!MC
{ 8XwAKN:f
new TestMethod(); {HeIY2
} _+K[1P
} r@+IDW.=9
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