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)); C Hyb{:<
} (J$JIPF
for(int i=0;i<nEndPos.length-1;i++) $N:m 9R
{ LvhF@%(9J
nEndPos = nStartPos[i+1]; lt5~rH2
} tul5:}x3
nEndPos[nEndPos.length-1] = nFileLength; JFR,QUT
} |VaXOdD`&
} }5zH3MPQH
/DZKz"N
+!.=M8[
//启动子线程 jO!!. w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b3y@!_'c
for(int i=0;i<nStartPos.length;i++) }w"laZ*
{ kmo3<'j{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gq+!%'][P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i#(T?=VPcy
nStartPos,nEndPos,i); ~;Xdz/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a8A8?:
fileSplitterFetch.start(); B>|@XfPM
} o)Ob}j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jw"'ZW#W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 83)2c a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M6y:ze
nEndPos = " + nFileLength); !3?HpR/nV
// fileSplitterFetch[nPos.length-1].start(); *<s|WLMG
CW, Kw
0u)]1
//等待子线程结束 d}ue/hdw
//int count = 0; jJ|O]v$N
//是否结束while循环 >(~;V;
boolean breakWhile = false; C!~&c7
GZ*cV3Y`&
NWv1g{M
while(!bStop) *jf (TIU
{ 0u-'{6
write_nPos(); 5 EDGl
Utility.sleep(500); @/B&R^aVZ
breakWhile = true; T4J(8!7
xNE<$Bz
~hYG%
for(int i=0;i<nStartPos.length;i++) H-^>Co_
{ N[E t
if(!fileSplitterFetch.bDownOver) p>65(&N,
{ dhsQfWg#}
breakWhile = false; co@Q
break; vYrqZie<
} o;_v'
} ^5j9WV
if(breakWhile) OpUC98p?@
break; h]vA%VuE'E
iS=}| 8"
WPpl9)Qc
//count++; j`='SzVloW
//if(count>4) (A/V(.!
// siteStop(); ^hRos
} MU%C_d%.
N1+%[Uh9)
[bH6>{3u
System.err.println("文件下载结束！"); "4oY F:h
} W@JmG`Sy
catch(Exception e){e.printStackTrace ();} (lTM^3 }
} g}P.ksM
Abd&p N
Z&/bp1
//获得文件长度 |SQ5Sb
public long getFileSize() \C~Y
{ d%u|) =7
int nFileLength = -1; bjZcWYT
try{ >N{K)a
URL url = new URL(siteInfoBean.getSSiteURL()); (9{)4[3MAG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '8}*erAg
httpConnection.setRequestProperty("User-Agent","NetFox"); d^!)',`
L6J=m#Ld
-*M/,O
int responseCode=httpConnection.getResponseCode(); _U|s!60'
if(responseCode>=400) ?8)_,
{ }{J<Wzw
processErrorCode(responseCode); ntK#7(U'
return -2; //-2 represent access is error l-4+{6lz
} AT*J '37
/=4 m4
>.'rN>B+
String sHeader; c%,@O&o
H809gm3(Z
l`"i'P
for(int i=1;;i++) 5M6`\LyU
{ B q/<kEgM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YhQ;>Ko
//Utility.log(in.readLine()); Lso4ZZ;
sHeader=httpConnection.getHeaderFieldKey(i); 7tbM~+<0
if(sHeader!=null) zb<YYJ]
{ Am>^{qh9
if(sHeader.equals("Content-Length")) -36pkC 6 \
{ Q[sj/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m][i-|@M
break; Y'n+,g
} 9*`(*>S
} )o4B^kq
else FZdZGK
break; UqsJ44QEZ
} :<Z>?x
} z _A]mJ
catch(IOException e){e.printStackTrace ();} Y7q=]
catch(Exception e){e.printStackTrace ();} Eu;f~ V
kF,_o/Jc
c-s A?q#|
Utility.log(nFileLength); 6sE%]u<V
SLGo/I*
]|6)'L&]*s
return nFileLength; <,:p?36
} )7`2FLG
,\".|m1o.
<4{Jm8zJ
//保存下载信息（文件指针位置） aFfd!a"n
private void write_nPos() a%FM)/oI|T
{ vZ0K1UTEXY
try{ V1h&{D\"
output = new DataOutputStream(new FileOutputStream(tmpFile)); L'A>IBrz
output.writeInt(nStartPos.length); q`u^ sc
for(int i=0;i<nStartPos.length;i++) 0UbY0sYo
{ "bhF`,V
// output.writeLong(nPos); ?q lpi(
output.writeLong(fileSplitterFetch.nStartPos); ;1gWz
output.writeLong(fileSplitterFetch.nEndPos); [p:mja.6y
} vGIe"$hNh
output.close(); A ,$CYLj+
} m,3H]
catch(IOException e){e.printStackTrace ();} D~^P}_e.
catch(Exception e){e.printStackTrace ();} *IGCFZbp41
} ' 5F3,/r
t5M"M{V
@,\J\ rb
//读取保存的下载信息（文件指针位置） OZSM2~
private void read_nPos() 1+Z@4;fk
{ QT<\E`v
try{ 1*VArr6*6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y' r I1eF
int nCount = input.readInt(); aS $ J `
nStartPos = new long[nCount]; ag*5fBF
nEndPos = new long[nCount]; ^T< HD
for(int i=0;i<nStartPos.length;i++) y$Rh$eK
{ rm5@dM@
nStartPos = input.readLong(); ~c\iBk
nEndPos = input.readLong(); 7]}2`^9
} s~tZN
input.close(); -TT{4\%s
} ;i>(r;ZM
catch(IOException e){e.printStackTrace ();} tso\bxiU
catch(Exception e){e.printStackTrace ();} #*~3gMI{=
} zu!#
<t"KNKI
`D,mZj/b
private void processErrorCode(int nErrorCode) v~AD7k2{8
{ o+%($p
System.err.println("Error Code : " + nErrorCode); p`=v$_]?(
} cGUsao
>V$ S\"
zEMZz$Y
//停止文件下载 :={rPj-nU
public void siteStop() MD+e!A#o
{ t^|GcU]
bStop = true; G]k+0&X
for(int i=0;i<nStartPos.length;i++) 3[cGSI"+
fileSplitterFetch.splitterStop(); oHR@*2b
zS/1v+
QZ2a1f'G
} M'sq{K9
} MY>*F[~ 2
//负责部分文件的抓取 ,1e\}^
**FileSplitterFetch.java pzFM#
*/ 557%^)v
package NetFox; $X ]t}=
i~i ?M)
4sM9~zC5
import java.io.*; m;oCi}fL
import java.net.*; ]?*L"()kp
n h&[e
HvJ-P#
public class FileSplitterFetch extends Thread { myqQqVW
`+]e}*7$f
=`/GBT$
String sURL; //File URL FC q&-
long nStartPos; //File Snippet Start Position g=Bge)
long nEndPos; //File Snippet End Position X(qs]:
int nThreadID; //Thread's ID +T8]R7b9
boolean bDownOver = false; //Downing is over .gs:.X)TG9
boolean bStop = false; //Stop identical w1:%P36H
FileAccessI fileAccessI = null; //File Access interface }:1*@7eR
HzZ.q2Zz%
jm&PGZ#n=R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5fuYva >Ik
{ Xp?WoC N
this.sURL = sURL; A(T=
this.nStartPos = nStart; gI{56Z
this.nEndPos = nEnd; a'|/=$
nThreadID = id; ?,oE_H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5z@QAQ
} 3bZ:*6W.6
>fx/TSql:J
.s`7n *xz
public void run() sUN9E4
{ CW'<Nh
while(nStartPos < nEndPos && !bStop) Po7oo9d
{ ^.u J]k0
3&5AbIZ
Wf>=^ ~`
try{ a @i?E0Fr
URL url = new URL(sURL); Q|tzA10E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (Z#j^}G_l
httpConnection.setRequestProperty("User-Agent","NetFox"); )@E'yHYO>
String sProperty = "bytes="+nStartPos+"-"; ~NZ}@J{00_
httpConnection.setRequestProperty("RANGE",sProperty); Dac ,yW
Utility.log(sProperty); n~'cKy)m
b0h>q$b
UmOK7SPi
InputStream input = httpConnection.getInputStream(); #waK^B)<a
//logResponseHead(httpConnection); :8l#jU`y
gbu@&
*ez7Q
byte[] b = new byte[1024]; Gn>~CoFN
int nRead; 9B2`FJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7-2,|(Xg
{ C)|#z/"
nStartPos += fileAccessI.write(b,0,nRead); o{xA{ @<
//if(nThreadID == 1) y0\=F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >IEc4
} '[Z.\
v0,&wdi
+Q&CIo
Utility.log("Thread " + nThreadID + " is over!"); m}GEx)Y D
bDownOver = true; {z*`* O@
//nPos = fileAccessI.write (b,0,nRead); U'Fc\M5l/l
} "j%L*J)
catch(Exception e){e.printStackTrace ();} %nT&
} [K#pU:lTH
} c*Q6k<SKR
8npjQ;%4>
QIu!o,B
//打印回应的头信息 %\?Gzc_
public void logResponseHead(HttpURLConnection con) pb}4{]sI
{ P(Z\y^S
for(int i=1;;i++) .tt=\R
{ #u$Z/,
String header=con.getHeaderFieldKey(i); fhbILg
if(header!=null) T[]kun
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +8|r_z\A5a
Utility.log(header+" : "+con.getHeaderField(header)); /<it2=
else H <ugc
break; V|G[j\]E<
} g0"KCX
} r:9H>4m
tqT-9sEXX.
2~q(?wY
public void splitterStop() DY!mq91
{ kH>^3(Q\
bStop = true; &$hT27A>k
} k ks ?S',
2-.%WhE/
2mVLR;s{_
} z{dn
>W?7a:#,
qD/FxR-!
/* qr[+^*Ha
**FileAccess.java N6*v!M+
*//文件访问(定位，写) *'hvYl/?>
package NetFox; )uIHonXU
import java.io.*; z]F4Z'(e.
3+| {O
H-Z1i
public class FileAccessI implements Serializable{ qvhol
_I}rQfPJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?{M!syD<
RandomAccessFile oSavedFile; /"%QIy'{
long nPos; 60St99@O
A`qb5LLJ)
$>mTPNF
public FileAccessI() throws IOException U?:<clh
{ jboQ)NxT!,
this("",0); H<6/i@ly
} $S0eERga
>4}2~;
qg;fh]j%
public FileAccessI(String sName,long nPos) throws IOException hf1f
{ |.zotEh
oSavedFile = new RandomAccessFile(sName,"rw"); dQ4K^u
this.nPos = nPos; X@ Gm:6
oSavedFile.seek(nPos); d.3O1TXK
} #815h,nP+
=7c1l77z
n|oAfJUk,
public synchronized int write(byte[] b,int nStart,int nLen) Eb<iR)e H=
{ $N#f)8v
int n = -1; ]'UO]i/
try{ F"-w
oSavedFile.write(b,nStart,nLen); =*YK6
n = nLen; |ei?s1)
} 0Up@+R2
catch(IOException e) 5M{DJ/q
{ Y@S?0
e.printStackTrace (); <4W"ne28
} '`Smg3T!~S
y^gazr"
A2b C5lA
return n; "kKIVlC
} ^#R-_I
u|=G#y;3
r'p;Nj.
} kQ$Q}3f
|*N.SS
%3i/PIN
/* Es kh=xA {
**SiteInfoBean.java $;_'5`xs
*/ 'r%`(Z{~
package NetFox; ,XW6W&vR;
.e2u)YqA
<v"C`cga
public class SiteInfoBean { !b*lL#s,Y
I~qS6#%r
-uiZp !
private String sSiteURL; //Site's URL _VR Sdr5
private String sFilePath; //Saved File's Path #Xri%&~
private String sFileName; //Saved File's Name M%:ACLYP
private int nSplitter; //Count of Splited Downloading File cW,wN~
4T6dju
`-4c}T
public SiteInfoBean() uG3t%CmN
{//nSplitter的缺省值为5 Z\xR+3
//default value of nSplitter is 5 KMznl=LF
this("","","",5); !xMyk>%2
} !wvP24"y
6Pl$DSu
Mno4z/4{A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K(Otgp+zb
{ <!&nyuSz
sSiteURL= sURL; r M'snW)
sFilePath = sPath; J']1^"_'
sFileName = sName; HPpKti7g
this.nSplitter = nSpiltter; f6^H Q1SSt
c3!d4mC:
.0#?u1gXsX
} Yv9(8
FgQd7p
*gu~7&yoP
public String getSSiteURL() UBi0 /
{ j;1X-
return sSiteURL; Eti;(>"@
} ,;H)CUe1"
GKtG#jZ&
{k}S!T
public void setSSiteURL(String value) RMmDcvM"k
{ +QuaQ% lA
sSiteURL = value; \Q?r+VZ
} r.[!n)*
ed2QGTgR
S!2M?}LU
public String getSFilePath() [$]vi`c2
{ 1'R]An BV
return sFilePath; F%lP<4Vx
} mE%H5&VSI
7 \!t/<
8"LvkN/v^
public void setSFilePath(String value) nv*q N\i'
{ F.?^ko9d
sFilePath = value; 5pI2G
} 7z)Hq./3@
41^+T<+
5K;jW
public String getSFileName() c# U!Q7J
{ yK_$6EtNKj
return sFileName; +S5"4<
} \eT0d<
8{8J(~
ux& WN ,
public void setSFileName(String value) 0[7\p\Q
{ ^0R.'XL
sFileName = value; /G9wW+1
} e]'ui<`
7MZBU~,r
d0"Hu^]
public int getNSplitter() yJ c#y
{ .EM0R\q
return nSplitter; C,P>7
} >Olg lUzA
uK6R+a
4%LGPh
public void setNSplitter(int nCount) B<u6Z!Pp2
{ o|*ao2a
nSplitter = nCount; X+z!?W*a
} F"1)y>2k
} zt/b S/
s {p-cV
lE=(6Q
/* 7xTgG!>v
**Utility.java 5I`j'j
*/ )y4bb^;z
package NetFox; l=ehoyER
gHpA@jdC*
VNBf2Va
public class Utility { *pK bMG#
{}kE=L5
kU{+@MA;
public Utility() {AUhF}O
{ <E/4/ ANN
AiKja>Fl<
KX D&FDkF
} 'APtY;x^{
R?MRRq
//线程睡眠 h\| ~Q.kG
public static void sleep(int nSecond) %Xc50n2Z
{ tIn dve
try{ `G7LM55
Thread.sleep(nSecond); sA$x2[*O
} {w:*t)@j
catch(Exception e) )r2$!(NQ
{ (#I$4Px{
e.printStackTrace (); ere h!
} j3>0oe!
} `#@#eZ
-':;0
//日志 (=&z:-52V
public static void log(String sMsg) O?\UPNb:K
{ 1g_p`(
System.err.println(sMsg); 7Z%EXDm4/c
} DBTeV-G9~R
<14,xYpE
TwPpZ@
public static void log(int sMsg) 9dS<^E(ZF
{ c{.y9P6
System.err.println(sMsg); , e^&,5b
} )M3}6^s]
} +vf~s^
^.3(o{g
`U4e]Qh/+
/* [A jY~
**TestMethod.java +az=EF
*/ e^!>W %.7Z
package NetFox; <Wrn/%tL
Y@(izC&h
\d-H+t]
public class TestMethod { =;L44.,g
ZNfQM&<d
wWYo\WH'
public TestMethod() ]g] ]\hS
{ ///xx/weblogic60b2_win.exe mETGYkPUa
try{ ol3].0Vc]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !)r1zSY"g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #'y4UN
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2I[(UMI$7
fileFetch.start(); "!S7D>2y#
} E\5Cf2Ox
catch(Exception e){e.printStackTrace ();} Z Jgy!)1n
O[Yc-4
m'n<.1;1{j
} -3GlpC22
Cfr2~w
`g}po%k
public static void main(String[] args) W?H-Ng3E
{ Hb&C;lk
new TestMethod(); %/n#{;c#
} SX)o0v+
} 0n/+X[%Ti
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