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)); 4&NB xe
} Kvg=7o
for(int i=0;i<nEndPos.length-1;i++) k$v7@|Aw
{ Mzg'$]N
nEndPos = nStartPos[i+1]; ZTTA??}Y
} HJr/N)d
nEndPos[nEndPos.length-1] = nFileLength; D&m1yl@\J
} P{dR pH|
} b!g)/%C
q5g_5^csM{
q<\r}1Dm
//启动子线程 ^:?z7m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ScJ:F-@>
for(int i=0;i<nStartPos.length;i++) (&m1*
{ Y#lAG@$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eQQVfEvS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6No.2Oo
nStartPos,nEndPos,i); ~^.,Ftkb@7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qF3S\ C
fileSplitterFetch.start(); nxN("$'cq
} 7h9oY<W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1%M^MT%&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Mxz X@GBX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3=]/+{B
nEndPos = " + nFileLength); /,7#%D
// fileSplitterFetch[nPos.length-1].start(); vasw@Uto)
HV`u#hZ7C
bY`Chb.
//等待子线程结束 6AD&%v
//int count = 0; Uj 3{c
//是否结束while循环 -C^qN7Bz
boolean breakWhile = false; [9?]|4
y~_x
A f?&VD4K
while(!bStop) w}}+8mk[
{ .WOF:Nu4
write_nPos(); 'PMzm/;8st
Utility.sleep(500); >VjtKSN
breakWhile = true; 3!;o\bgK
rGH7S!\AM
Ahd{f!
for(int i=0;i<nStartPos.length;i++) Kc9)Lzu+
{ tSDp>0yZ3
if(!fileSplitterFetch.bDownOver) 6w<p1qhW
{ ?fs#K;w
breakWhile = false; \l6mXIn=>
break; YVHDk7s
} w*SFQ_6YE
} kGq<Zmy|
if(breakWhile) n;b9f|&z
break; a(o[ bH.|;
0txSF^x
e ]>{?Z
//count++; If9!S} wa
//if(count>4) qmnCa&C9
// siteStop(); ]*S_fme
} =7P; /EV
DA4!-\bt@
] )x z
System.err.println("文件下载结束！"); ,KibP_<%&P
} $PbN=@
catch(Exception e){e.printStackTrace ();} OaxE3bDT
} ^_ZQf
Q^V`%+
**YNR:#Y
//获得文件长度 h$zPQ""8
public long getFileSize() +ACV,GG
{ +FVcrL@
int nFileLength = -1; .Lu=16
try{ :S7yM8b`
URL url = new URL(siteInfoBean.getSSiteURL()); qXW2a'~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N<Q}4%^c
httpConnection.setRequestProperty("User-Agent","NetFox"); `TsfscN
XWy iS\
Xhkw<XbV
int responseCode=httpConnection.getResponseCode(); B&Ci*#e
if(responseCode>=400) Y.*lO
{ SS~Txt75m
processErrorCode(responseCode); :U[_V4?7
return -2; //-2 represent access is error ?R{?Qv
} 0Rk'sEX,
;09J;sf
"RX?"pB
String sHeader; _&![s]
x}>tX
'}YXpB
for(int i=1;;i++) b~1p.J4
{ et ~gO!1:*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }EIwkz8
//Utility.log(in.readLine()); FW.dHvNX
sHeader=httpConnection.getHeaderFieldKey(i); >`\*{]
if(sHeader!=null) qiF~I0_0
{ g4$%)0x%
if(sHeader.equals("Content-Length")) X9gC2iSs]
{ pn7 :")Zx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tB3CX\e
break; tr/dd&(Y1
} i:8^:(i
} 7VXeu+-P
else C[&&.w8Pm
break; Y-c~"#
} i }gxq
} 7~Ga>BK
catch(IOException e){e.printStackTrace ();} -pGt;
catch(Exception e){e.printStackTrace ();} eo_T.q
Q%xY/xH]
k51s*U6=
Utility.log(nFileLength); udZ: OU<
#rr-4$w+
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return nFileLength; fBOPd=
} -d3y!|\>a
66Xt=US
g&vEc1LNo
//保存下载信息（文件指针位置） ` ;=Se_
private void write_nPos() ,;-*q}U
{ e,*[5xQ
try{ LG|,g3&
output = new DataOutputStream(new FileOutputStream(tmpFile)); L-R}O 8
output.writeInt(nStartPos.length); qU n>
for(int i=0;i<nStartPos.length;i++) bC{8yV=)
{ KTEis!w
// output.writeLong(nPos); MX0B$yc$
output.writeLong(fileSplitterFetch.nStartPos); \-0`%k"&
output.writeLong(fileSplitterFetch.nEndPos); RHbp:Mlk
} JrAc]=
output.close(); !v L:P2
} {@$3bQ
catch(IOException e){e.printStackTrace ();} =x'%zUgE
catch(Exception e){e.printStackTrace ();} -*M:OF"Zh
} ~m?~eJK#a
1F,_L}=o1s
o?FUVK
//读取保存的下载信息（文件指针位置） q_&IZ,{Vk
private void read_nPos() <6~;-ZQY
{ !?*!"S-Sl
try{ sK?-@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5,ahKB8
int nCount = input.readInt(); 6w;|-/:`
nStartPos = new long[nCount]; .A/H+.H;
nEndPos = new long[nCount]; !VZj!\I
for(int i=0;i<nStartPos.length;i++) PWu2;JF
{ NF!1)
nStartPos = input.readLong(); r_E)HL/A
nEndPos = input.readLong(); Z|%2495\
} 3]es$Jy
input.close(); # :w2Hf6Q
} ONiI:Z>%
catch(IOException e){e.printStackTrace ();} ]Hy PJ
catch(Exception e){e.printStackTrace ();} E57{*C
} ha! "BR
ok2~B._+;
a3O_#l-Z
private void processErrorCode(int nErrorCode) X",0VO
{ ](:FW '-
System.err.println("Error Code : " + nErrorCode); Q5n :f+
} Pm(:M:a
g+)\/n|
8I0Tu
//停止文件下载 PZRn6Tc
public void siteStop() ~C7<a48x
{ rOb"S*
bStop = true; ]NV ]@*`tO
for(int i=0;i<nStartPos.length;i++) eSNSnh]'
fileSplitterFetch.splitterStop(); n(YHk\2
"IS^ajaq
cievC,3*
} lN>C#e<]
} 65#:2,s
//负责部分文件的抓取 {V%O4/
**FileSplitterFetch.java \R\@t]>Y
*/ 0&IXzEOr
package NetFox; q,+kPhHEgy
"Lq|66
*8.@aX3
import java.io.*; 'Rd*X6dv
import java.net.*; N^(lUba
s~X*U&}5
,,gLrVk
public class FileSplitterFetch extends Thread { @PoFxv
[7Lxt
W#jZRviyq!
String sURL; //File URL Iei7!KLW
long nStartPos; //File Snippet Start Position u@_!mjXQ
long nEndPos; //File Snippet End Position ~K-*q{6Q
int nThreadID; //Thread's ID B5,QJ W*
boolean bDownOver = false; //Downing is over &M3ES}6
boolean bStop = false; //Stop identical UcLNMn|
FileAccessI fileAccessI = null; //File Access interface Jhsv2,8 {
zP(=,)d
C7 ]DJn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f UF;SqT
{ l P$r
this.sURL = sURL; u2-@?yt
this.nStartPos = nStart; ocl47)
this.nEndPos = nEnd; &xBK\
nThreadID = id; '`]n_$f'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x #tu
} e@:P2(WWl
,]uX:h-EM
q]N?@l]
public void run() EN-H4F
{ ~S^X"8(U
while(nStartPos < nEndPos && !bStop) ?VZ11?u
{ Y0PGT5].@'
h-La'}>?
^s2m\Q(
try{ \U!@OX.R'M
URL url = new URL(sURL); [EmOA.6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;;YcuzQI3
httpConnection.setRequestProperty("User-Agent","NetFox"); OHHNWg_5
String sProperty = "bytes="+nStartPos+"-"; 9'n))%CZ.
httpConnection.setRequestProperty("RANGE",sProperty); XJmFJafQD
Utility.log(sProperty); e|b~[|;*=
T,WKoB
Jm %ynW
InputStream input = httpConnection.getInputStream(); Ns.3s7&
//logResponseHead(httpConnection); [arTx^
){+[$@9
a1g6}ym\
byte[] b = new byte[1024]; kUn2RZ6$#
int nRead; f`hyYp`d5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }iua] 4|
{ QGH h;
nStartPos += fileAccessI.write(b,0,nRead); selP=Q!
//if(nThreadID == 1) ?{ B[^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |jahpji6
} (VYR!(17
"WYA
NZo<IKD$
Utility.log("Thread " + nThreadID + " is over!"); w0Fwd
bDownOver = true; 01LZE,.
//nPos = fileAccessI.write (b,0,nRead); =5y`(0 I`U
} tS\=<T
catch(Exception e){e.printStackTrace ();} &l.x:eD
} JsmbW|t^
} 6R;)
M`0(!Q}
N@Xg5huO
//打印回应的头信息 ug^om{e-
public void logResponseHead(HttpURLConnection con) 9?uqQ
{ e7@li<3>d
for(int i=1;;i++) G*i.a*9<)
{ XVQL.A7
String header=con.getHeaderFieldKey(i); 0jR){G9+
if(header!=null) 8#+`9GI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); paW'R+Rck
Utility.log(header+" : "+con.getHeaderField(header)); .aNO( /kO
else f%2%T'Q
break; p QluGIX0V
} bt;lq!g
} qE>i,|rP`
jEUx q%BH
SK's!m:r=
public void splitterStop() hIR@^\?
{ @. "q
bStop = true; 7egq4gN]2Y
} \WWG>OUh.U
%fHH{60
aT&t_^[]
} p` $fTgm
avlqDi1l
s~L`53A
/* Q-[3j
**FileAccess.java (FuEd11R
*//文件访问(定位，写) SGt5~Txj
package NetFox; 8+9\7*
import java.io.*; ze&#i6S
vyE{WkZxR
oWI!u 5
public class FileAccessI implements Serializable{ "c6<zP
?fV?|ZGZI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C?/r;
RandomAccessFile oSavedFile; /^Y[*5
long nPos; DacN{r"3
6;gLwOeOHY
1DUb [W8
public FileAccessI() throws IOException x.ba|:5
{ sMP:sCRC
this("",0); /N>} 4Ay
} K!p,x;YX
*,17x`1e
+,z)#
public FileAccessI(String sName,long nPos) throws IOException e^zHw^js
{ JRXRi*@
oSavedFile = new RandomAccessFile(sName,"rw"); i0\)%H:z
this.nPos = nPos; SnW7x
oSavedFile.seek(nPos); tU{\ev$x
} m^Glc?g<
44~hw:
j1A|D
public synchronized int write(byte[] b,int nStart,int nLen) 33 :@*
{ X &D{5~qC
int n = -1; D^|9/qm$
try{ a$}NW.
oSavedFile.write(b,nStart,nLen); gGEIK0\{
n = nLen; z3W3=@
} Yk'm?p#~
catch(IOException e) wN(&5rfS
{ 9Sz7\W0
e.printStackTrace (); DHv2&zH
} wG8 nw;
;}K62LSR
wx*1*KZ
return n; i'=2Y9S}
} ~>g+2]Bn>$
%m`zWg-
dw9Tf^V
} L=]p_2+
0q#"clw
w#9_eq|3
/* :RiF3h(
**SiteInfoBean.java 8Q=ZH=SQK
*/ _~&9*D$ {>
package NetFox; pawl|Z'Ez
yQ%"U^.m
~x#vZ=]8
public class SiteInfoBean { Om9jtWk
JNi=`X&A
N 9LgU)-Jt
private String sSiteURL; //Site's URL Q|c|2byb
private String sFilePath; //Saved File's Path -{{[cTI
private String sFileName; //Saved File's Name VD[pZ2;4
private int nSplitter; //Count of Splited Downloading File G\kpUdj}
:G=FiC
59lj7
public SiteInfoBean() <cj{Qk
{//nSplitter的缺省值为5 ]iVLHVqz
//default value of nSplitter is 5 u-:Ic.ZV
this("","","",5); 4TZ cc|B5
} cP rwW6
jDX>izg;V
(>7>3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -c+]Wm"\
{ Ej"u1F14J
sSiteURL= sURL; h/m6)m.D
sFilePath = sPath; |`0n"x7
sFileName = sName; gKi{Y1
this.nSplitter = nSpiltter; |]sx+NlNc
H M:r0_
v"!4JZ%K
} #{PmNx%M
yWb4Ify
^R~~L
public String getSSiteURL() Z a(|(M H
{ e|lD:_1i
return sSiteURL; uM S*(L_
} v("wKHWTI@
L0"~[zB]N
J^ G
public void setSSiteURL(String value) 2*1ft>Uty
{ MbA\pG'T
sSiteURL = value; +B"0{>n}F
} xDjV`E]
nc?B6IV
|.U)ll(c
public String getSFilePath() {' 5qv@3
{ rRb+_]Lg
return sFilePath; ^4pto$#@O:
} ,hRN\Kt)p
FHg0E++?
N#k61x
public void setSFilePath(String value) &c%Y<1e`%
{ ^jSsa
sFilePath = value; uY#TEjGh]
} }NCL>l;q
dh -,E
o\=n4;S
public String getSFileName() #wR;|pN
{ D4u%6R|F
return sFileName; X#p Wyo~
} A9:NKY{z
)!W45"l-3M
I'!/[\_
public void setSFileName(String value) Wf26
{ !8RwO%c(
sFileName = value; anN#5jt
} osP\DiQ
=Lp7{09u
=o7}]k7
public int getNSplitter() +OHGn;C
{ K[?Xm"4
return nSplitter; 5.0e~zlM-
} [(mlv42"
K_&MoyJJ9f
1KE:[YQ1
public void setNSplitter(int nCount) _aS;!6b8W
{ Gc,_v3\
nSplitter = nCount; +[-i%b3q
} +9A\HQ|22
} ]uh3R{a/
DXR:1w[^
A[N{
/* [.,>wo~
**Utility.java j}JZ
*/ gzn^#3b
package NetFox; MgMD\
k;^ :
{S.>BXX
public class Utility { mTDVlw0dh
*%FA:Y
6" B%)0
public Utility() x!<yT?A
{ t+Bf#:
/bRg?Q
]$iqa"{
} :l u5Uu~
2f:^S/.A
//线程睡眠 Sm{>rR
public static void sleep(int nSecond) Q[4: xkU
{ wIvo"|%
try{ %yS3&Ju
Thread.sleep(nSecond); `)$_YZq|SR
} ro~+j}*
catch(Exception e) #s5N[uK^m
{ JK_OZ
e.printStackTrace (); }?8uH/+ZA
} Yl cbW0'c
} ed!>)Cb
~.g3ukt
//日志 )X+mV
public static void log(String sMsg) ?\=/$Gt
{ oMH.u^b]fT
System.err.println(sMsg); <'U]`Lp
} 4Ft1@
{Tp2H_EG
Rd*[%)
public static void log(int sMsg) E+95WF|4k"
{ ~+F;q vq
System.err.println(sMsg); rJyCw+N0
} J4$! 68
} %|W.^q
?X$,fQ#F|
sN=6gCau
/* xl9aV\W
**TestMethod.java pL1i|O
*/ OW;tT=ql
package NetFox; $D1w5o-
C@\{ehG
]jMKC8uz
public class TestMethod { 6=_~0PcY
c7uG9
\;5\9B"i
public TestMethod() f>jwN@(
{ ///xx/weblogic60b2_win.exe )=pD%$iq
try{ OTWkUB{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }j5 a[L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J97R0
SiteFileFetch fileFetch = new SiteFileFetch(bean); a dfR!&J
fileFetch.start(); w&h2y4
} 6rti '
catch(Exception e){e.printStackTrace ();} I5ss0JSl/
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+\ _{x/u1
} q Dd~2"er
^?"\?M1
,:n| ?7
public static void main(String[] args) 4Aes#{R3v
{ q}|U4MJm
new TestMethod(); % ~]xuP[
} +ZsX*/TOn
} q(o/yx{bm
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