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)); |M>k &p,B-
} 4H?Ma|,
for(int i=0;i<nEndPos.length-1;i++) CPeK0(7Zh
{ HU+H0S~g
nEndPos = nStartPos[i+1]; _rJSkZO
} Z_~DTO2Qg
nEndPos[nEndPos.length-1] = nFileLength; FEmlC,%
} gj;G:;1m
} uWj-tzu
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j77}{5@p
//启动子线程 ~MQf($]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q%1;{5
for(int i=0;i<nStartPos.length;i++) T2; 9
{ WA5kX SdIb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), esFL<T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [eP]8G\ W
nStartPos,nEndPos,i); #7T={mh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J5IJy3d
fileSplitterFetch.start(); u.Yb#?
} X*"O'XCA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bd*(]S9d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O~OWRJ@p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A3pQ?d[
nEndPos = " + nFileLength); @BhAFv,7
// fileSplitterFetch[nPos.length-1].start(); /?xn
9cj-v}5j
\^LR5S&
//等待子线程结束 {/!Gh\i
//int count = 0; vkgL"([_
//是否结束while循环 Q^w]Nj(e_
boolean breakWhile = false; pdiZ"pe
"Oko|3
[E7@W[xr
while(!bStop) Jz0S2&
{ =V 7w CW
write_nPos(); KptLeb:Om
Utility.sleep(500); ..TjEBp
breakWhile = true; <F & hfy
'B6H/d>
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for(int i=0;i<nStartPos.length;i++) hzo,.hS's
{ :/l
if(!fileSplitterFetch.bDownOver) 1&"1pH
{ 0^Cx`xdX:
breakWhile = false; ScKfr
break; tb\pjLB][
} 8!>pFVNJf
} AR3=G>hO,
if(breakWhile) L"/ato
break; D9C; JD
CnYX\^Ow
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//count++; k8V0-.UL}
//if(count>4) Wh_c<E}&
// siteStop(); CI'5JOqP
} E/;YhFb[
\c}r6xOr
V%=t2+
System.err.println("文件下载结束！"); K$]B" s
} ?%ntO]
catch(Exception e){e.printStackTrace ();} x=N;>
} 1<|I[EI
P[i/o#
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//获得文件长度 ':$a6f &T
public long getFileSize() eqCB2u"Jq
{ R"([Y#>m
int nFileLength = -1; ?0Zw ^a
try{ _0E,@[
URL url = new URL(siteInfoBean.getSSiteURL()); xII!2.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]XyJ7esg
httpConnection.setRequestProperty("User-Agent","NetFox"); So`"z[5
{rLOAewr
;A!i V|
int responseCode=httpConnection.getResponseCode(); *2;3~8Y
if(responseCode>=400) Cz)D3Df^
{ T]2q >N
processErrorCode(responseCode); kzXW<V9
return -2; //-2 represent access is error R FiR)G ,
} |-D.
N2J!7uoQ
2fB@zF
String sHeader; S5TT
e?WR={
u*`GIRfWT
for(int i=1;;i++) (p!AX<=z
{ -<=<T@,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wf1DvsJQl
//Utility.log(in.readLine()); Qpq0j^\
sHeader=httpConnection.getHeaderFieldKey(i); {*9i}w|2
if(sHeader!=null) ?]N&H90^5
{ Q-5wI$=
if(sHeader.equals("Content-Length")) bmpB$@
{ t+ ]+Gn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,#loVLy
break; .*"IJD9
} U+ =q_ <
} rfoCYsX'
else _Hk`e}}
break; yI<'J^1C[
} I|H mbTXa
} i,T{SV
catch(IOException e){e.printStackTrace ();} N0PX<$y
catch(Exception e){e.printStackTrace ();} YeJdkt
p4 PFoFo2
ppjrm
Utility.log(nFileLength); nv]64mL3
|t_2AV
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return nFileLength; {r)M@@[
} ,P+&-}gn9
m>_'f{&u
m<4Lo0?nS
//保存下载信息（文件指针位置） ZxWV,s&p
private void write_nPos() L6.R?4B
{ /o2eKx
try{ ."O(Ig[
output = new DataOutputStream(new FileOutputStream(tmpFile)); i1C'
output.writeInt(nStartPos.length); <0m;|Ai'W
for(int i=0;i<nStartPos.length;i++) R?Qou!*]
{ Kw|`y %~
// output.writeLong(nPos); ZlzFmNe60
output.writeLong(fileSplitterFetch.nStartPos); { L5m`-x
output.writeLong(fileSplitterFetch.nEndPos); ~-/AKaK}
} m/AN*`V
output.close(); FCPbp!q6
} /2@@v|QL
catch(IOException e){e.printStackTrace ();} @ 2_&ti
catch(Exception e){e.printStackTrace ();} w[&BY
} vI@8DWs
->(B:Cz
79DC]48M
//读取保存的下载信息（文件指针位置） 5Fl|=G+3@g
private void read_nPos() C#R9Hlb
{ ghl9gFFj
try{ .^23qCs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3'wBX
int nCount = input.readInt(); p:jrqjLp
nStartPos = new long[nCount]; )UJMmw\
nEndPos = new long[nCount]; D[mYrWHpn
for(int i=0;i<nStartPos.length;i++) jI%yi-<;
{ <#-ERQw
nStartPos = input.readLong(); )j]RFt
nEndPos = input.readLong(); Lnzhs;7L
} DH%X+r
input.close(); .uP$M(?j
} OZ6%AUot
catch(IOException e){e.printStackTrace ();} 92i#It}-/
catch(Exception e){e.printStackTrace ();} ~ocr^V{"<~
} wHmEt ORo
;b^@o,=
e_I 8Jj4
private void processErrorCode(int nErrorCode) ]rS+v^@QH
{ C1J'. !
System.err.println("Error Code : " + nErrorCode); -_3.]o/J
} H;6V
o>YRKb
2-4%h!
//停止文件下载 qA30G~S
public void siteStop() 5eYCnc9
{ /[OMpP
bStop = true; OX"`VE
for(int i=0;i<nStartPos.length;i++) R+\5hI@ >i
fileSplitterFetch.splitterStop(); };*5+XY^
]%."
&Lw| t_y
} [o~w>,a
} ZD/!C9:&.0
//负责部分文件的抓取 ;p/@tr9
**FileSplitterFetch.java 8c9_=8vw
*/ &Ru6Yt0W
package NetFox; Dz?F,g_
c1`o3gb
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import java.io.*; l},%g%}iMU
import java.net.*; p82qFzq#
i=ba=-"Mt
j{vzCRa>8
public class FileSplitterFetch extends Thread { MI/1uw
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String sURL; //File URL KH;e)91
long nStartPos; //File Snippet Start Position &zZSWNW
long nEndPos; //File Snippet End Position ^%L$$V nG
int nThreadID; //Thread's ID 'BC-'Ot
boolean bDownOver = false; //Downing is over Y9WH%
boolean bStop = false; //Stop identical iG;6e~p
FileAccessI fileAccessI = null; //File Access interface x~W&a*WNT
()rDM@
7G/"!ePW6`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pO^ 6p%
{ (<ejJPWT
this.sURL = sURL; U5klVl
this.nStartPos = nStart; R:E`
this.nEndPos = nEnd; O/Fzw^
nThreadID = id; vn8Ez6<27
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qRUz;M4
} 'g#))y
'D1@+FFU0
b7$?'neH/.
public void run() CB~&!MdMr
{ &(K*TB|Om
while(nStartPos < nEndPos && !bStop) f /jN$p
{ Gqs8$[o
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cIgF]My*D@
try{ K= 69z
URL url = new URL(sURL); !} 1p:@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qRU8uu
httpConnection.setRequestProperty("User-Agent","NetFox"); {M=tw
String sProperty = "bytes="+nStartPos+"-"; a7+BAma<
httpConnection.setRequestProperty("RANGE",sProperty); <Z vG&
Utility.log(sProperty); =q._Qsj?fu
o5)U3U1|
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InputStream input = httpConnection.getInputStream(); f.,-KIiF
//logResponseHead(httpConnection); 9+L! A
Q/< $ (Y
)P$ IXA\
byte[] b = new byte[1024]; Nk7Q
int nRead; P"- ,^?6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X\h]N
{ p5*i d5
nStartPos += fileAccessI.write(b,0,nRead); 39OZZaWL
//if(nThreadID == 1) Bp}<H<@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cD{[rI E3
} r6^DD$X
]Z~H9!%t
`0sa94H1[
Utility.log("Thread " + nThreadID + " is over!"); IlwY5iL
bDownOver = true; E_xpq
//nPos = fileAccessI.write (b,0,nRead); mFvw s
} H}:apRb
catch(Exception e){e.printStackTrace ();} Bdq/Ohw|!
} 7_JK2
} )q#b^( v
%1#5 7-
hX;xbl
//打印回应的头信息 ~oOOCB
public void logResponseHead(HttpURLConnection con) [E=t{&t
{ GE"#.J4z
for(int i=1;;i++) tnp]wZ
{ rtY0?
String header=con.getHeaderFieldKey(i); n&@\[,B
if(header!=null) Gs-'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \ Xuu|]
Utility.log(header+" : "+con.getHeaderField(header)); j88H3bi0
else 7)[4|I
break; iX4/;2B=,
} 9m<>G3Jr
} )2\6Fy0S
N 4Dyec\
*iYs,4
public void splitterStop() &359tG0@P
{ nkvzv
bStop = true; byd[pnI$H
} GXsHc,
x5{ zGv.j
lT*Hj.
} %GAEZH,2sG
rQ/S|gG
S9mj/GpL3
/* e\/Lcng
**FileAccess.java 6tP^_9njy
*//文件访问(定位，写) Zr`:A$
package NetFox; N2C^'dFj
import java.io.*; XO\P4x:c
8on2BC2
OrHnz981K
public class FileAccessI implements Serializable{ H]YPMG<
9!PJLI=D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l^&#fz
RandomAccessFile oSavedFile; U{HJNftdpm
long nPos; sHKT]^7
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1J^{h5?lU
public FileAccessI() throws IOException -p9|l%W
{ g,9o'fs`x
this("",0); J8(v65
} U2!9Tl9".
{ImZ><xe/
7j{SCE;
public FileAccessI(String sName,long nPos) throws IOException J}lBKP:-*
{ Z5\u9E"]
oSavedFile = new RandomAccessFile(sName,"rw"); Zs)HzOP)9
this.nPos = nPos; J,k9?nkY /
oSavedFile.seek(nPos); ;Cm%<vW4!
} 6EJ,czt(
NO"=\Zn6
]{Iy<
public synchronized int write(byte[] b,int nStart,int nLen) )mJl-u[0+
{ 4mUQVzV
int n = -1; 7 zK%CJ
try{ ~-JkuRJ\
oSavedFile.write(b,nStart,nLen); lY0^Z
n = nLen; &R>x;&Gj
} b=.Ikt+y
catch(IOException e) mM1\s>o
{ D.4=4"qMi
e.printStackTrace (); #~ UG9@a
} p-r}zc9@
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r`VKb
return n; ,H\EPmNHK
} We_/:=
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79=w]y
} o|(-0mWBQA
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<e)3 j6F!
/* &p`RKD
**SiteInfoBean.java 5 J61PuH
*/ Sr/"'w;
package NetFox; D8qZh1w%A|
5&\Q0SX(~
#8QQZdC8`
public class SiteInfoBean { ~~]L!P
PL[7|_%
1\TXb!OtL
private String sSiteURL; //Site's URL kuqf(
private String sFilePath; //Saved File's Path RL SP?o2J
private String sFileName; //Saved File's Name Gr}Lp
private int nSplitter; //Count of Splited Downloading File s=#3f3
>y &9!G
H~e;S#3_v
public SiteInfoBean() &%$r3ePwc
{//nSplitter的缺省值为5 ci <`*>l
//default value of nSplitter is 5 /9QI^6&SX
this("","","",5); *O+G}_}
} ;*[nZV>
1Y_Cd
A90oX1l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZC@sUj"
{ $RfM}!7?
sSiteURL= sURL; XL1v&'HLV
sFilePath = sPath; E?m(&O j
sFileName = sName; M`-.0
this.nSplitter = nSpiltter; cF7I
5VDqx@(
%tT&/F
} 5^~%10=
|x3.r t
m(L]R(t
public String getSSiteURL() 51u8.%{4
{ 06|+_
return sSiteURL; `B}(Ln
} %+ynrg-
_pnJ/YE
3.Oc8(N^}
public void setSSiteURL(String value) y'(l]F1]
{ PF+v[h;,
sSiteURL = value; "qYPi
} G'{$$+U^K
mp:%k\cF|
7y1J69IK
public String getSFilePath() mzLDZ#=b
{ I9-vV>:z
return sFilePath; C0eP/d
} _@3@_GE
nlQ<Aa-%
C0|<+3uND=
public void setSFilePath(String value) '5\7>2fI
{ @kw#\%Uz
sFilePath = value; %6}S1fuA
} \BOZhXfl'
'8R5?9"
wuSp+?{5k
public String getSFileName() u=JI 1
{ RcIGIt
return sFileName; t."hAvRL
} Dm?>U1{
rV>/:FG
fgVeB;k|
public void setSFileName(String value) [#S}L(
{ H|T!}M>
sFileName = value; I0trHrX9
} G%_6"s
- |n\
.{%~4$yu7
public int getNSplitter() gDU~hv
{ t84(kzcC
return nSplitter; 5-3`@ (/
} ]PJb 9$f2
UE^_SZ
tkx1iBW=
public void setNSplitter(int nCount) ;3wj(o0
{ P#m/b<
nSplitter = nCount; # Y/.%ch.
} c%%r
} xs_l+/cZ
zA4m !l*eM
BQq,,i8H
/* b1Bu5%bt,:
**Utility.java `@eo <6
*/ =LEKFXqM
package NetFox; WDc2Qt
l ps 6lnh
{-;lcOD
public class Utility { *)+1BYMo
Z".mEF-b
1sKKmtgH
public Utility() 8q*MhH>6I
{ 22lC^)`TE
eq+t%
vcTWe$;Q
} R r7r5
6yEYX'_
//线程睡眠 Z |wM
public static void sleep(int nSecond) 7 \)OWp
{ LnZzY0
try{ P[{qp8(g
Thread.sleep(nSecond); {?tK]g#
} /c/t_xB
catch(Exception e) Y Y4"r\V
{ E=!=4"rZF
e.printStackTrace (); $@k[Xh
} 8;2UP`8s?
} j.UQLi&`
O9y4.`a"
//日志 dm;H0v+Y'
public static void log(String sMsg) CMI'y(GN
{ xE%1C6~C<
System.err.println(sMsg); OL+dx`Y
} 8`Wj 1 ,q
q0|u vt"
pm$ZKM
public static void log(int sMsg) u%n6!Zx
{ +76{S_CZ
System.err.println(sMsg); V mxVE=l
} ]C.x8(2!f
} U^jxKBq^
qFEGV+
1n}q6oa=
/* WmU5YZ(mAq
**TestMethod.java WXz'H),R
*/ ;M,u,KH)/
package NetFox; C? pi8Xg
+-_71rJc.
eZDqW)x
public class TestMethod { :B(F?9qK
o+(>/Ou
,nn5LQ|l.j
public TestMethod() `m2e *
{ ///xx/weblogic60b2_win.exe 52+;j[ ]/O
try{ !<9sOvka{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2kg<O%KA`c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "E`;8SZa
SiteFileFetch fileFetch = new SiteFileFetch(bean); %ux%=@%
fileFetch.start(); QoZ7l]^
} -dX{ R_*
catch(Exception e){e.printStackTrace ();} |Z%I3-z_DS
h{zE;!+)D
/Mk85C79
} @**@W[EM
a& >(*PQ
ua$H"(#c
public static void main(String[] args) Q y(Gy'q~
{ sj;8[Xy's
new TestMethod(); >7@kwj-f)
} $Pa7B]A,Ae
} uK6_HvHuy
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