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)); w4,]2Ccn.
} /&(1JqzlB
for(int i=0;i<nEndPos.length-1;i++) m6i%DE
{ J(e7{aRJ9
nEndPos = nStartPos[i+1]; hg8Be6G<
} DvYwCgLR
nEndPos[nEndPos.length-1] = nFileLength; %'0&ElQ
} 4-V)_U#8
} O,|\"b1(
3cixQzb}u
?mU\ N0o
//启动子线程 3;l"=#5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M|8 3HTJ
for(int i=0;i<nStartPos.length;i++) W Y:s gG
{ 6G}c1nWU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h55>{)(E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MwAJ(
nStartPos,nEndPos,i); 8teJ*sz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .YR8v1Cp
fileSplitterFetch.start(); 'I v_mig
} *ik/p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #tDW!Xv?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y)Tl<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5g>wV
nEndPos = " + nFileLength); yFjVKp'P
// fileSplitterFetch[nPos.length-1].start(); |dk[cX>
8W -@N
1 i3k
//等待子线程结束 xA #H0?a]
//int count = 0; k':s =IXW
//是否结束while循环 6t7fa<
boolean breakWhile = false; vq>l>as9O
k>5O`Y:
;LQ9#M?
while(!bStop) ,Sg33N?
{ opD-vDa h
write_nPos(); mmP U
Utility.sleep(500); L/i(KF{
breakWhile = true; ARWZ; GX
D:JS)+]
9i%9
for(int i=0;i<nStartPos.length;i++) :1;Q(9:v
{ %K1")s
if(!fileSplitterFetch.bDownOver) bfdVED
{ p/*"4-S
breakWhile = false; #epy%>
break; pbLGe'
} d~Mg vh'
} IzUo0D*@
if(breakWhile) af'@h:
break; *aRX \TnN
<n^3uXzD
Gx'TkU=
//count++; fu]N""~
//if(count>4) H~o <AmE0!
// siteStop(); /S~m)$vu
} A,#2^dR
SaO3zz@L
.=<$S#x^Hb
System.err.println("文件下载结束！"); E FY@Y[
} o8ppMM8_R[
catch(Exception e){e.printStackTrace ();} XUSvhr$|
} !#}7{
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H l<$a"K7\
//获得文件长度 Cq\I''~8
public long getFileSize() :2y"3azxk
{ "HlgRp]u
int nFileLength = -1; Ns=AjhLc z
try{ "b,%8
URL url = new URL(siteInfoBean.getSSiteURL()); +iA=y=;blH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NXU`wnVJ
httpConnection.setRequestProperty("User-Agent","NetFox"); aE/D*.0NI
lddp^ #f
cdTsRS;E
int responseCode=httpConnection.getResponseCode(); |B^G:7c
if(responseCode>=400) xs!p|
{ ~uj;qq
processErrorCode(responseCode); ln<]-)&C
return -2; //-2 represent access is error 6rX_-Mm6w
} Xy7Z38G
TH?9< C-C
+sZUJ
String sHeader; ;t(f1rPyE
qf8[!5GM
/:[2'_Xl
for(int i=1;;i++) {{!Y]\2S
{ H{(]9{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I1"MPx{
//Utility.log(in.readLine()); YQ]\uT>}&
sHeader=httpConnection.getHeaderFieldKey(i); !;3PG9n3|h
if(sHeader!=null) a07=tD
{ uaw<
if(sHeader.equals("Content-Length")) @i%YNI5*
{ 76H!)={
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .p&Yr%~
break; n&Yk<
} ]Pc^#=(R0
} A3{0q>CC
else ziEz.Wn"
break; '&yeQ
} jbmTmh1q
} <@uOCRbV
catch(IOException e){e.printStackTrace ();} la^ DjHA$
catch(Exception e){e.printStackTrace ();} vkcRm`.
#A<P6zJXR
0q6I;$H
Utility.log(nFileLength); ~<9{#uM
B'weok
%fjuG
return nFileLength; z#Nl@NO&
} :`Az/U[
.EP6oKA
vqNsZ 8|`
//保存下载信息（文件指针位置） 5#2F1NX
private void write_nPos() hOk00az
{ ,mFsM!|
try{ R;}22s
output = new DataOutputStream(new FileOutputStream(tmpFile)); yR71%]*.
output.writeInt(nStartPos.length); =A!S/;z>
for(int i=0;i<nStartPos.length;i++) [L~@uAMw:
{ ,/,9j{|"j
// output.writeLong(nPos); :Vuf6,
output.writeLong(fileSplitterFetch.nStartPos); O'DW5hBL0
output.writeLong(fileSplitterFetch.nEndPos); lU2c_4
} rrBAQY|.
output.close(); KMK`F{
} HOi C
catch(IOException e){e.printStackTrace ();} E]} n(
catch(Exception e){e.printStackTrace ();} A74920X`W
} ,|T7hTn=
-yx/7B5@
nU z7|y
//读取保存的下载信息（文件指针位置） g:#dl\k
private void read_nPos() !<\Br
{ v"Jgw;3
try{ W WG /k17
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pW?&J>\6
int nCount = input.readInt(); }_OM$nzj
nStartPos = new long[nCount]; fI|[Z+"
nEndPos = new long[nCount]; 1|QvN1?
for(int i=0;i<nStartPos.length;i++) 5g ;ac~g
{ d/,E2i{I7
nStartPos = input.readLong(); 8cxai8
nEndPos = input.readLong(); NAFsFngqH
} 'r}fZ
input.close(); UlovXb
} v3RcwySk
catch(IOException e){e.printStackTrace ();} V5rp.~
catch(Exception e){e.printStackTrace ();} ^]c6RE_
} tj1JB%
qr(`&hB-L
4? (W%?
private void processErrorCode(int nErrorCode) !.HnGb+
{ g!J0L7i|
System.err.println("Error Code : " + nErrorCode); /Z%>ArAx
} @R2at
4Yjx{5QSAG
HAB#pd9
//停止文件下载 $#NQ<3
public void siteStop() uGJ"!K
{ sd0r'jb
bStop = true; _YHu96H;
for(int i=0;i<nStartPos.length;i++) @,H9zrjVFZ
fileSplitterFetch.splitterStop(); HZ"Evl|n
f-RK,#^?,
E;(Rm>lB
} aP()|js
} ^ @=^;nB
//负责部分文件的抓取 B|{I:[
**FileSplitterFetch.java 3:CO{=`\7B
*/ ;h/pnmhP
package NetFox; 2j&@p>
{padD p
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import java.io.*; /!&R9!6 :
import java.net.*; ]]iPEm"@
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o|8`>!hF
public class FileSplitterFetch extends Thread { 8g/F)~s^F
V64L,u#`l
7^e +
String sURL; //File URL 1(dj[3Mt
long nStartPos; //File Snippet Start Position )mcEQ-!b
long nEndPos; //File Snippet End Position fys
int nThreadID; //Thread's ID ]F*3"y?)2
boolean bDownOver = false; //Downing is over ^HA %q8| n
boolean bStop = false; //Stop identical `iG,H[t+j
FileAccessI fileAccessI = null; //File Access interface VM=+afY5M
D&:yMp(
o4^Fo p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @e2}BhB2
{ NYB[Zyp
this.sURL = sURL; 12`_;[37
this.nStartPos = nStart; v> z@
this.nEndPos = nEnd; \ZXLX'-
nThreadID = id; 7*H:Ob)9k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x8#ODuH
} SAv<&
`k{& /]
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public void run() omX?Bl
{ $.mQ7XDA9
while(nStartPos < nEndPos && !bStop) TYgQJW?
{ |$lwkC)O
u:gtOjk2
e]>ori 8
try{ 3/6/G}s
URL url = new URL(sURL); ZU2laqa_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A2H4k|8
httpConnection.setRequestProperty("User-Agent","NetFox"); g[z.*y/
String sProperty = "bytes="+nStartPos+"-"; Ss?CfRM
httpConnection.setRequestProperty("RANGE",sProperty); :VA.QrKW
Utility.log(sProperty); M^madx6`
_GtBP'iN
U yqXMbw@
InputStream input = httpConnection.getInputStream(); B5am1y{P#
//logResponseHead(httpConnection); 8nNsrat
C'mL&
Hgc=M
byte[] b = new byte[1024]; W 0[N0c
int nRead; Uu p(6`7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) keAcKhj
{ }E^S]hdvz
nStartPos += fileAccessI.write(b,0,nRead); VV_l$E$
//if(nThreadID == 1) B0UJq./`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R!x: C!{
} 76fIC
Pt< s* (
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Utility.log("Thread " + nThreadID + " is over!"); B/uniR^x
bDownOver = true; wFn[9_`*
//nPos = fileAccessI.write (b,0,nRead); ~4,I7c7
} ><?BqRm+
catch(Exception e){e.printStackTrace ();} `m~syKz4A
} V`hu,Y;%
} e_3CSx8Cc
D$eB ,~
jdqj=Yc
//打印回应的头信息 WgGm#I>K
public void logResponseHead(HttpURLConnection con) 7Hw<ojkt
{ }odV_WT
for(int i=1;;i++) |01?w|
{ ,Fqz e/
String header=con.getHeaderFieldKey(i); pb;")Q'
if(header!=null) (zo^Nn9VJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =d;Vk
Utility.log(header+" : "+con.getHeaderField(header)); !cEG}(|h
else $A\m>*@
break; ekSY~z=/u
} :K.4n
} P1zK2sL_
!E\[SjY@J
}qPhx6nP
public void splitterStop() Zy"=y+e!E;
{ tB(4Eq \
bStop = true; f>Td)s1 M
} ),^eA
6iezLG5
PFSLyV*
} W=}Okq)x9I
yWIm&Q:
Xo5$X7m
/* h\[\\m O
**FileAccess.java /ONV5IkPy
*//文件访问(定位，写) !3&kQpF
package NetFox; Eh8Pwt7C@
import java.io.*; 2h~-
jh ez
yf1CXldi
public class FileAccessI implements Serializable{ ;1AG3P'
EYS>0Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =Ov7C[(
RandomAccessFile oSavedFile; Do-^S:.
long nPos; {i{xo2<1"
#~ v4caNx
H. ,;-
public FileAccessI() throws IOException [.yJV`
{ =5]n\"/
this("",0); ?^!,vh
} yOXO)u1n
YZ}cB
K\!#4>yd
public FileAccessI(String sName,long nPos) throws IOException C*Vd-U
{ l)8&Ip
oSavedFile = new RandomAccessFile(sName,"rw"); <+`(\
this.nPos = nPos; ReB7vpd
oSavedFile.seek(nPos); F}?<v8#z0
} x4?10f(9=
o3Ot.9L
f|3q^wjs
public synchronized int write(byte[] b,int nStart,int nLen) N_wp{4 0/
{ ks(SjEF
int n = -1; Ws[D{dS/
try{ a=}*mF[ug
oSavedFile.write(b,nStart,nLen); ;6;H*Y0,|E
n = nLen; P~$<X
} 'A{h iY
catch(IOException e) R'K/t|MC
{ eBr4O i
e.printStackTrace (); F#r#}.B='U
} X~U >LLr
`x8Bn"
8QgA@y"
return n; xh9qg0d
} I+?hG6NM
rs8\)\z
B&KL2&Z~Pq
} {ShgJ;! Q
f4t.f*#
Un=a fX?j
/* +Ghi}v
**SiteInfoBean.java r#876.JK
*/ y=N"=Z
package NetFox; Q4'C;<\@(Q
dDcZ!rRaL@
kEN#u
public class SiteInfoBean { %CH6lY=lI
]?l{j
0%C^8%(x
private String sSiteURL; //Site's URL C0C0GqN,
private String sFilePath; //Saved File's Path H'g?llh1J
private String sFileName; //Saved File's Name 4cgIEw[6
private int nSplitter; //Count of Splited Downloading File 0irr7Y
=]>%t]
4*H"Z(HP
public SiteInfoBean() >%%=0!,yX
{//nSplitter的缺省值为5 -$k>F#
//default value of nSplitter is 5 xF8S*,#,*
this("","","",5); I}0_nge
} J1F{v)T'?
j'rS&BIG
m2bDHQ+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6qp5Xt+
{ I44s(G1jl
sSiteURL= sURL; wz(K*FP
sFilePath = sPath; 440FhDMj
sFileName = sName; pWaPC/,g
this.nSplitter = nSpiltter; /p`&;/V|
Fz"ff4Bx [
f05d ;
} zmFws-+A
~9M!)\~
;IP~Tb]&
public String getSSiteURL() D!3{gV#
{ &w\I<J`T
return sSiteURL; yXfMzG
} P'[<AZ
m#@_8_ M
hl/itSl$
public void setSSiteURL(String value) "ED8z|]j
{ :{}_|]>K
sSiteURL = value; .KA V)So"
} EQ >t[ &
M}FWBs'*|
Bq}x9C&<
public String getSFilePath() =Viy^ieN$
{ V|?WF&
return sFilePath; mUXk9X%n
} sg?@qc=g
ZXXiL#^
>M4"|W U_
public void setSFilePath(String value) =4NqjSH
{ ;bjnL>eW
sFilePath = value; .]t5q%}j
} /=T"=bP#/
L]-w;ll-
;iX<`re~
public String getSFileName() YMB~[]$V<
{ 3)E(RyQA3
return sFileName; Y`li> .\
} >)Dhi+D
,;iA2
JeQ[qQ
public void setSFileName(String value) s-D?)
{ >;lKLGJrd>
sFileName = value; \Ow,CUd
} ~<O,Vs_C/
,b.n{91[]x
wh6&>m#r
public int getNSplitter() GW m4~]0E
{ _wu*M
return nSplitter; P[i\e7mR
} 2P}I'4C-
f1cl';
`BT^a =5
public void setNSplitter(int nCount) )U98
{ aqL<v94wX
nSplitter = nCount; YKx 1NC
} Jt=>-Spj
} g9V.13k
5' \)`
Y3oMh,
/* n<R \w''x
**Utility.java lX;mhJj!
*/ MUwVG>b8J~
package NetFox; AzjMv6N
h}6_ybmZ
tgN92Q.i6T
public class Utility { #5{sglC"|F
j%xBo:
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public Utility() H@W0gK(cS;
{ V5s&hZZYa
]P3[.$z
P\(30
} LknVqZ|k
rm|7 [mK
//线程睡眠 %V_eJC""?
public static void sleep(int nSecond) mw+j|{[
{ jT^!J+?6K+
try{ 0xP:9rm
Thread.sleep(nSecond); {hd-w4"115
} OmNn,PCl8
catch(Exception e) -Enbcz(B
{ I~RcOiL)
e.printStackTrace (); Phlk1*1n
} \(u@F<s-
} mQ,{=C=D
Xp^$ E6YFy
//日志 :~-i&KNk
public static void log(String sMsg) Lz6*H1~
{ 2oB?Dn
System.err.println(sMsg); <7RfBR.9
} <.$,`m,
rw*M&qg!z
t-EV h~D1p
public static void log(int sMsg) B$7[8h
{ VM;g+RRq
System.err.println(sMsg); e6m1NH4,
} f\'G`4e
} F@^N|;_2
PP4d?+;V
5"2@NL
/* =1Sy@MbH3
**TestMethod.java !E0fGh
*/ MPG+B/P&
package NetFox; g RU-g
gV`S%
$i%HDt|
public class TestMethod { m3"c (L`B
dqz1xQ1
Sj1r s#@1
public TestMethod() swt\Ru6,
{ ///xx/weblogic60b2_win.exe 4k*qVOBa6R
try{ %mmxA6I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gix>DHq$k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @Yarz1
SiteFileFetch fileFetch = new SiteFileFetch(bean); `skH-lk,
fileFetch.start(); %IU4\ZY>
} 5~yQ>h
catch(Exception e){e.printStackTrace ();} d'q&Lq
"c EvFY
8J^d7uC
} +7^w9G
i&pMF O
Ej5^Y ?-6
public static void main(String[] args) #:I^&~:
{ N.vG]%1"
new TestMethod(); d3(+ztmG!
} 2{gwY85:
} 2D_6
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