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)); @dGj4h.
} =*}|y;I
for(int i=0;i<nEndPos.length-1;i++) R`Q9|yF\
{ JPmW0wM
nEndPos = nStartPos[i+1]; h T4fKc7P
} [gU z9iU
nEndPos[nEndPos.length-1] = nFileLength; EyozhIV
} x#U?~6.6
} WG9x_X&XJ
zDC-PHFHQ
41$7P[M;
//启动子线程 [9X1;bO#f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <wa}A!fu
for(int i=0;i<nStartPos.length;i++) iB{O"l@w
{ LvB-%@n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /,wG$b+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >wZ!1Jq
nStartPos,nEndPos,i); CJ?Lv2Td
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ._#|h5
fileSplitterFetch.start(); p^NYJV
} UDhW Y.`'~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #VtlXr>G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?NJ\l5'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &vo]l~.
nEndPos = " + nFileLength); R:-^,/1
// fileSplitterFetch[nPos.length-1].start(); 0Bb amU
N_h)L`
H+t^eg88
//等待子线程结束 "|(+~8[
//int count = 0; BoXQBcG]w
//是否结束while循环 ur"ckuG!9
boolean breakWhile = false; 5yuR[VU
njX!Ez
6*Rz}RQ
while(!bStop) LC2t,!RRl&
{ ]hc.cj`\W&
write_nPos(); [ q22?kT
Utility.sleep(500); y1B3F5
breakWhile = true; 8nW#Q<s
1Sr@$+VGO
LsoP >vJG
for(int i=0;i<nStartPos.length;i++) uee2WGD
{ \f05(ld
if(!fileSplitterFetch.bDownOver) &K/5AH"q
{ kF`2%g+
breakWhile = false; gCW.;|2
break; :voQ#f=
} Syo1Dq6z.
} bR(rZu5
if(breakWhile) H4MFTnJ{
break; d?.ewsC
{a\m0Bw/
"xi)GH]H_
//count++; KYZ/b8C
//if(count>4) ]W]o6uo7
// siteStop(); NN>,dd3T
} =;4cDmZh
\IQf|
A7C+-N
System.err.println("文件下载结束！"); T32C=7
} $b QD{ {
catch(Exception e){e.printStackTrace ();} N[~RWg
} iG!tRNQ{y
Dqs{n?@n
cR*D)'/tl
//获得文件长度 ~K5eO-
public long getFileSize() X3P~z8_
{ 4 bw8^
int nFileLength = -1; E.R,'Y;x
try{ Ivmiz{Oii
URL url = new URL(siteInfoBean.getSSiteURL()); lQ {k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .i) H1sD
httpConnection.setRequestProperty("User-Agent","NetFox"); <j+DY@*
bx#GOK-
/PafIq
int responseCode=httpConnection.getResponseCode(); ZBUEg7c
if(responseCode>=400) n<+g{QHi
{ |Ah'KpL8W
processErrorCode(responseCode); w^6rgCl
return -2; //-2 represent access is error `A_CLVE
} KmG*`Es
W1dpKv
8M<q-sn4B
String sHeader; d="Oge8
@GNNi?EY
i7_Nv
for(int i=1;;i++) 1RgtZp%
{ D2z" Z@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7o_1PwKS6
//Utility.log(in.readLine()); j^-E,YMC
sHeader=httpConnection.getHeaderFieldKey(i); mnh>gl!l
if(sHeader!=null) ;x^WPYEj
{ .jA'BF.
if(sHeader.equals("Content-Length")) P:,'
{ >\6Tm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bFD vCF
break; K%h9'}pq>1
} ux`)jOQ`Y]
} <&^P1x<x
else 6O"?wN%$
break; |Ii[WfFA|J
} .0+=#G>
} :Aj8u\3!@
catch(IOException e){e.printStackTrace ();} GrPKJ~{6
catch(Exception e){e.printStackTrace ();} ieo Naq
lQ(I/[qVd
-5B>2K F
Utility.log(nFileLength); X67^@~l
Aj#bhv
tUU`R{=(
return nFileLength; 8S/SXyS
} *'[8FZ|dQ
@-ps[b`z
?&A)%6` ~
//保存下载信息（文件指针位置） w*#B_6bG
private void write_nPos() }x!=F<Q!r
{ ]z3!hgTj
try{ >n3w'b
output = new DataOutputStream(new FileOutputStream(tmpFile)); uy'm2
output.writeInt(nStartPos.length); qw?#~"Ca.
for(int i=0;i<nStartPos.length;i++) u-qwG/$E
{ :x88
// output.writeLong(nPos); $]LhE:!G
output.writeLong(fileSplitterFetch.nStartPos); OD{()E?1B
output.writeLong(fileSplitterFetch.nEndPos); ~C M%WvS
} w(Jf;[o
output.close(); pV:;!+
} X?'ShXI
catch(IOException e){e.printStackTrace ();} "}ibH{$lM
catch(Exception e){e.printStackTrace ();} B}S!l>.z
} K!~j}z*
}\ kLh(
r:N =?X`N
//读取保存的下载信息（文件指针位置） LL% Aw)Q`
private void read_nPos() 1'Sr0 oEd3
{ C.]\4e
try{ 4gD;XNrV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :DWvH,{+&
int nCount = input.readInt(); WX~:Y,l+u
nStartPos = new long[nCount]; ]]Bqte
nEndPos = new long[nCount]; l$_q#Kd
for(int i=0;i<nStartPos.length;i++) OeMI
{ vX?MB
nStartPos = input.readLong(); Lsu_f'p0
nEndPos = input.readLong(); >%6a$r~@
} ]cQYSN7!SY
input.close(); ({&\~"
} Y6W#uiqk
catch(IOException e){e.printStackTrace ();} U)v){g3w)
catch(Exception e){e.printStackTrace ();} ?`T0zpC
} |)5xmN]
IkWV|E
oyw*Z_9~
private void processErrorCode(int nErrorCode) a%nksuP3
{ n1XJuc~
System.err.println("Error Code : " + nErrorCode); mH`K~8pRg
} =1ltX+
9!XXuMWU<
/FJ.W<hw
//停止文件下载 :<}1as!eo
public void siteStop() "kb[}r4?
{ {^8->V
bStop = true; WR|n>i@m
for(int i=0;i<nStartPos.length;i++) bv:M zYS
fileSplitterFetch.splitterStop(); s8:-*VR9
P55QE+B
+4 W6{`
} +jD*Jtb<
} W _b!FQ]
//负责部分文件的抓取 jK(]eiR$S
**FileSplitterFetch.java reP)&Fo
*/ VsU*yG a
package NetFox; bT>1S2s
2|a5xTzH
!#[B#DZc(
import java.io.*; rd_!'pG
import java.net.*; ]nIH0k3y
;9&#Sb/
6Mc&gnN
public class FileSplitterFetch extends Thread { Ot<vn34mt:
r+RFDg/
KT3n-Y-,
String sURL; //File URL *DDqa?gQb
long nStartPos; //File Snippet Start Position b}APD))*H!
long nEndPos; //File Snippet End Position (J6>]MZ#)
int nThreadID; //Thread's ID /}\Uw
boolean bDownOver = false; //Downing is over QJ4=*tX)
boolean bStop = false; //Stop identical ztEM>xsk
FileAccessI fileAccessI = null; //File Access interface _8 C:Md`
N\{{:<Cp\
<sncW>?!~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?y/LMja
{ $eu-8E'
this.sURL = sURL; ,@Fde=Lw
this.nStartPos = nStart; j1~'[
this.nEndPos = nEnd; 0rrNVaM
nThreadID = id; 1 !8 b9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t,]E5,1
} xg.o7-^M
eAl;:0=%L
xJ rKH
public void run() Spm0DqqR?
{ }!_ofe
while(nStartPos < nEndPos && !bStop) 7Zw.mM!i
{ 2kfX_RK
bXNM.K
#S|DoeFs
try{ 6%A_PP3Z
URL url = new URL(sURL); X,mqQ7+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i-FsA
httpConnection.setRequestProperty("User-Agent","NetFox"); b#[EkI 0@
String sProperty = "bytes="+nStartPos+"-"; SJ8CBxA
httpConnection.setRequestProperty("RANGE",sProperty); B:]%Iu|
Utility.log(sProperty); PZ.q
&:?2IAe
A(@VjXl
InputStream input = httpConnection.getInputStream(); 5Tg[-tl
//logResponseHead(httpConnection); ozOvpi:k3%
O<>cuW(l
elDt!9Pu
byte[] b = new byte[1024]; _&R lR
int nRead; @%b&(x^UD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TbQ5
{ N<e72x
nStartPos += fileAccessI.write(b,0,nRead); |*5HNP
//if(nThreadID == 1) ZnNl3MKV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1m4Xl%KS>
} yt[vd8O'c
e.'6q ($3
*Sw1b7l
Utility.log("Thread " + nThreadID + " is over!"); jU2vnGw_
bDownOver = true; MO-7yp:K
//nPos = fileAccessI.write (b,0,nRead); o>jM4sk$
} Ad)::9K?J
catch(Exception e){e.printStackTrace ();} 6k+4R<
} WlHK
} X:kr$
> }fw7X
Bm$(4
//打印回应的头信息 _^MkC}8
public void logResponseHead(HttpURLConnection con) *LOUf7`
{ 1+ib(MJ<:#
for(int i=1;;i++) hM "6-60
{ AI,Jy%62/
String header=con.getHeaderFieldKey(i); U-ADdOh"q
if(header!=null) zI{~;`tzN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vE{L`,\q
Utility.log(header+" : "+con.getHeaderField(header)); PC)aVr?@@
else c`O(||UZT
break; (T|q]29
} Ba#wW E
} chakp!S=
Vk:] aveW
.8dlf7* ,
public void splitterStop() "pMx(
{ kCHYLv3.
bStop = true; tl"?AQcBR
} yOswqhz
yFY:D2
l|j}Ggen
} yp?a7t M
%DhM}f
srQ]TYH ,
/* C8W4~~1S
**FileAccess.java 9D[Jn}E:
*//文件访问(定位，写) /8Ru O
package NetFox; 0BrAgv"3a_
import java.io.*; HY2*5#T
7'zXf)!
><wYk)0E
public class FileAccessI implements Serializable{ O6"S=o&
6%a:^f]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @8eQ|.q]Q
RandomAccessFile oSavedFile; *?3c2Jg=E
long nPos; Ku`u%5<
$(fhO
.K`EflN
public FileAccessI() throws IOException ;ZoEqMv
{ wfQ^3HL
this("",0); b Od<x >@
} FH)_L1n
>K n7A
5>\~jf
public FileAccessI(String sName,long nPos) throws IOException )>;V72
{ 952l1c!
oSavedFile = new RandomAccessFile(sName,"rw"); *;:dJXR
this.nPos = nPos; oM(8'{S=
oSavedFile.seek(nPos); }l7@:ezZZ7
} :^rt8>~
N~|Z@pU"
X" Upml
public synchronized int write(byte[] b,int nStart,int nLen) mlix^P
{ c^1tXu|&
int n = -1; $*+IsP!
try{ sc&u NfJ
oSavedFile.write(b,nStart,nLen); X'J!.Jj
n = nLen; Xv<K>i>k
} ({0:1*lF@
catch(IOException e) *CCh\+S7m
{ VT [TE
e.printStackTrace (); -?p4"[
} {Jc.49
:Z&<5
^v5<*uf%m
return n; <Uc?#;%Y}
} fM`.v+
)F_nK f"a
-pW*6??+?
} Q<>b3X>O
5tl($j
Q 6n!u;
/* 3IG<Ot9
**SiteInfoBean.java "A]#KTP
*/ -*$ s ;G#
package NetFox; Zo<j"FG
mtmTlGp6Lc
eX'U d%
public class SiteInfoBean { ]$i@^3`[w
^Lv)){t
apgR[=Oy
private String sSiteURL; //Site's URL [`kk<$=,&
private String sFilePath; //Saved File's Path w+u1"
private String sFileName; //Saved File's Name NwyNl
private int nSplitter; //Count of Splited Downloading File L;-V Yo#
an2Yluc;
<q&4Y+b
public SiteInfoBean() 8d7 NESYl
{//nSplitter的缺省值为5 ^[6el_mj
//default value of nSplitter is 5 ..7"<"uH
this("","","",5); ^^B~v<uK
} ly#jl5wmT
I-^C6~
yoH,4,!G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MML=J~1
{ %-woaj
sSiteURL= sURL; Wv||9[Rd
sFilePath = sPath; &2bqL!k
sFileName = sName; "7Z-ACyF5
this.nSplitter = nSpiltter; *x:*Q \|
mKsJ[)#.
~REfr}0
} [2PPa9F
;0lY_ii
_2TL>1KZt
public String getSSiteURL() 24u_}ZQzY
{ _#qfe
return sSiteURL; sC A
} =Z ql6D
E=Vp%08(
L1Jn@
public void setSSiteURL(String value) )|/%]@` N
{ g`C\pdX"B
sSiteURL = value; <eZ*LK?
} [HI$[:[
U!(es0rX
~dk97Z8
public String getSFilePath() qw 03]a
{ ~F8xXW0
return sFilePath; pxn@rN#*
} Y,Lx6kU
5>lIrBf
&->ngzg
public void setSFilePath(String value) '&nQ~=3
{ M@o^V(j
sFilePath = value; Cu!]-c{
} JT&RaFX
>}:
1m5*MY
public String getSFileName() 3W%j^nM
{ s(KSN/
return sFileName; bz}-[W+
} .TCDv4?
pD('6C;
5M/~|"xk
public void setSFileName(String value) dI|D c
{ jweX"G54R
sFileName = value; rsq?4+\
} }|%1LL^pB
hI9q);g
<PiO %w{
public int getNSplitter() &isKU8n
{ AvPPsN0
return nSplitter; OJd/#KFm
} [N12X7O3
d&\3}uH
Z&79: 9=#>
public void setNSplitter(int nCount) G:3szz
{ p{}4#+-<#H
nSplitter = nCount; A$]s{`
} k?$I4&|5Nt
} Cv}^]_`Q
NWP!V@WG
}=}wLm#&1
/* |-;VnC&UY
**Utility.java <uxLG;R
*/ On54!m
package NetFox; 2v2XU\u{t
tt#dO@G#Fe
6oKdw|(Q#
public class Utility { 'uE;8.,
.T)wG;+
TkJ[N4'0
public Utility() #f<v%
{ tbWfm5$
{VKFw=$8
]Axz}:
} EY:IwDA.}
:m(DRD
//线程睡眠 '_^T]fr}
public static void sleep(int nSecond) z:@:B:E
{ r fzNw
try{ Zazff@O *
Thread.sleep(nSecond); ^5.XQ0n
} dI&Q5M8
catch(Exception e) TL)*onA9
{ _CfJKp)
e.printStackTrace (); g`%in
} cPD_=.&
} &w#!
j:xC\b47"
//日志 ?C#E_
public static void log(String sMsg) ~MBPN4r
{ \+l*ZNYM3
System.err.println(sMsg); Yj#tF}nPC
} NcP/W>lN
jj1\oyQ8
'3Lu_]I-
public static void log(int sMsg) OQ7 `n<I<)
{ .w;kB}$YC
System.err.println(sMsg); -^5467
} u8]FJQ*\6+
} h693TS_N
<^'{=A>
#{vC =m73
/* %IX)+ Lp`
**TestMethod.java jx]P:]
*/ W*t] d
package NetFox; BMy3tyO
@phVfP"M
\ l#eW x
public class TestMethod { 5&V=$]t
])o{!}QUl\
%/"n(?$W
public TestMethod() aL( hWE
{ ///xx/weblogic60b2_win.exe 1[^YK6a/
try{ #3QPcoxa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b7Jxv7$e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iN[x *A|h
SiteFileFetch fileFetch = new SiteFileFetch(bean); oojl"j4
fileFetch.start(); z@i4
} $[A\i<#
catch(Exception e){e.printStackTrace ();} pYx,*kG:HW
D]]wJQU2
viG,z4Zf
} )63 $,y-;$
=c'4rJ$+
kIVQ2hmv
public static void main(String[] args) {d'-1z"q
{ pA~}_
new TestMethod(); >%k6k1CZ
} k~^4
} MQQm3VaKS
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