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)); |jniI(
} WLEjRx
for(int i=0;i<nEndPos.length-1;i++) s3W)hU)
{ C9U~lcIS
nEndPos = nStartPos[i+1]; wz5xJ:Tj
} :~pPB#)nk
nEndPos[nEndPos.length-1] = nFileLength; Q9Wa@gi|
} x5k6yHn
} J A ]s
T2 0dZ8{y
e;56}w
//启动子线程 g6k@E,cI_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jAmAT/1
for(int i=0;i<nStartPos.length;i++) ojzO?z
{ 1y l2i|m+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Aq}]{gfQ1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;GO>#yg4Eh
nStartPos,nEndPos,i); 74rz~ZM 5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [ottUS@
fileSplitterFetch.start(); C+$dm)M/q
} `(<XdlOj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <SUjz}_Oa:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K.n #;|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [>Kkj;*
nEndPos = " + nFileLength); BDyOX6
// fileSplitterFetch[nPos.length-1].start(); s"<k)Xi
-@-cG\{
R 28v5
//等待子线程结束 Zi[@xG8dm
//int count = 0; SY_T\ }
//是否结束while循环 9`+c<j4/B
boolean breakWhile = false; a1B_w#?8
&96I4su
>Qz#;HI
while(!bStop) .R;HH_
{ F_U3+J>
write_nPos(); |AW[4Yn>
Utility.sleep(500); &F*s.gL
breakWhile = true; .{LFc|Z[
)V%xbDdS
={-\)j
for(int i=0;i<nStartPos.length;i++) =xWZJ:UnU
{ hV])\t=yf
if(!fileSplitterFetch.bDownOver) Ap !lQ>p
{ .|=\z9_7S8
breakWhile = false; ItCv.yv35
break; @ .KGfNu
} O H7FkR
} \Og+c%
if(breakWhile) I2DpRMy
break; H[|~/0?K
L rPkxmR
.sA.C]f
//count++; =Runf +}
//if(count>4) G/ 5%.Bf@
// siteStop(); t:c.LFrF
} 'm9` 12H
t>sE x:
6zn5UW#q
System.err.println("文件下载结束！"); Er[A X.3
} 6@Y|"b
catch(Exception e){e.printStackTrace ();} ?hM64jI|
} iR0y"Cii
,2)6s\]/b
RGX=)
//获得文件长度 DeYV$W B
public long getFileSize() P }uOJVQ_
{ HorDNRyu
int nFileLength = -1; U%<Inb}ad
try{ [8*)8jP3
URL url = new URL(siteInfoBean.getSSiteURL()); -{+}@?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *9i{,I@
httpConnection.setRequestProperty("User-Agent","NetFox"); PxE3K-S)G
>OK^D+v"j
v9UD%@tZ
int responseCode=httpConnection.getResponseCode(); -!9G0h&i|
if(responseCode>=400) o? $.fhD
{ ;UP$yM;
processErrorCode(responseCode); [fIg{Q
return -2; //-2 represent access is error Tac$LS\Q
} 3D(0=$W
RX5dO%
t()c=8qF|u
String sHeader; d`6 'Z
Hq 188<
Xs?o{]Fe
for(int i=1;;i++) 5 u0HI
{ $tS}LN_!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MqUH',\3
//Utility.log(in.readLine()); k#rBB
sHeader=httpConnection.getHeaderFieldKey(i); !v0LBe4
if(sHeader!=null) .6'qoo_N
{ &8 x-o,
if(sHeader.equals("Content-Length")) {.\TtE
{ (!N|Kl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m9Hit8f@Q
break; >e"#'K0?\
} ;d9QAN&0}
} !GGkdg*-*9
else #N cK X
break; Z)aUt Srf
} 4_cqT/
} # 4PVVu<
catch(IOException e){e.printStackTrace ();} E+w<RNBmz
catch(Exception e){e.printStackTrace ();} N*&1GT#9
8pgEix/M5o
9 |vLwQ
Utility.log(nFileLength); ox (%5c)b|
,nB5/Lx
/gkX38
return nFileLength; N'`A?&2ru
} /RC7"QzL
0=E]cQwh
!=P1%
//保存下载信息（文件指针位置） <yFu*(Q
private void write_nPos() C-[eaHJ'$
{ Gk /fBs
try{ OH(waKq2I
output = new DataOutputStream(new FileOutputStream(tmpFile)); J6FV]Gpv
output.writeInt(nStartPos.length); kq,ucU%>p
for(int i=0;i<nStartPos.length;i++) KNIn:K^/
{ Da&]y
// output.writeLong(nPos); ah+iZ}E%
output.writeLong(fileSplitterFetch.nStartPos); $@"g^,n
output.writeLong(fileSplitterFetch.nEndPos); EA]U50L(
} ` v@m-j6
output.close(); b7?hI
} @7j AL-
catch(IOException e){e.printStackTrace ();} K}MK<2vU
catch(Exception e){e.printStackTrace ();} h|{]B,.Lh
} JHTSUq
Vt&2z)Zz
Y^EcQzLw
//读取保存的下载信息（文件指针位置） =.]4;z
private void read_nPos() S2VA{9:m
{ s{\8om'-
try{ T!WT;A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F%D.zvKN
int nCount = input.readInt(); EVC]sUT
nStartPos = new long[nCount]; &H/'rd0M
nEndPos = new long[nCount]; '=8d?aeF
for(int i=0;i<nStartPos.length;i++) qm8B8&-
{ Fgh_9S9J
nStartPos = input.readLong(); \B,@`dw
nEndPos = input.readLong(); ~^fZx5
} My[pr_xg
input.close(); JL}_72gs
} c>:wd@w
catch(IOException e){e.printStackTrace ();} 62o:,IcoG
catch(Exception e){e.printStackTrace ();} k],Q9
} $OkBg0
iYm-tsER;
>T3-
private void processErrorCode(int nErrorCode) 3z9d!I^>k
{ -g Sa_8R
System.err.println("Error Code : " + nErrorCode); /quc}"__
} Tg)|or/%
[KaAXv .X
$f=J2&D,Cz
//停止文件下载 Wk4s reB
public void siteStop() Pz|>"'
{ J76kkW`5
bStop = true; Jg\zdi:t
for(int i=0;i<nStartPos.length;i++) ~{B7 k:
fileSplitterFetch.splitterStop(); u9GQU
9gEwh<
KNpl:g3{<Q
} u4F5h PO]
} lC("y' ::
//负责部分文件的抓取 ~>Fu5i $i
**FileSplitterFetch.java i8[t=6Rm@
*/ 5Y'qaIFR
package NetFox; ?o4C;
Qu"\wE^.`
ag#S6E^%S
import java.io.*; ,+vy,<e&
import java.net.*; ith 3=`3
[OV"}<V
eH3JyzzP,
public class FileSplitterFetch extends Thread { aS{n8P6vW
k,E{C{^M
5k3b3&
String sURL; //File URL N~d?WD\^
long nStartPos; //File Snippet Start Position (Hz^)5(~
long nEndPos; //File Snippet End Position UkT=W!cq
int nThreadID; //Thread's ID |\<`Ib4j
boolean bDownOver = false; //Downing is over eJVjuG
boolean bStop = false; //Stop identical J^nBdofP
FileAccessI fileAccessI = null; //File Access interface W*4-.*U8a
#!qm ZN
m!4ndO;0vh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YX7L?=;.@
{ 8'.Hyy@;
this.sURL = sURL; EXwo,?I
this.nStartPos = nStart; z(exA
this.nEndPos = nEnd; f/NH:1)y
nThreadID = id; {3p4:*}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C:* *;=.
} -MO#]K3<
+p_CN*10H
\H~T>j{N
public void run() wd^':
{ |zNX=mAV
while(nStartPos < nEndPos && !bStop) b#Z{{eLny
{ 69?wc!
}DEg-j,F
[f-?ymmT
try{ }[};IqVaK
URL url = new URL(sURL); Ae^~Cz1qz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JEwa &
httpConnection.setRequestProperty("User-Agent","NetFox"); [0[i5'K:
String sProperty = "bytes="+nStartPos+"-"; @* jz o
httpConnection.setRequestProperty("RANGE",sProperty); Uq,^Wy
Utility.log(sProperty); +I:Unp
cAqLE\h
(KD RkE|=
InputStream input = httpConnection.getInputStream(); "f2$w
//logResponseHead(httpConnection); 9y8&9<#
3{^9]7UC
n;Q7X>-f8`
byte[] b = new byte[1024]; /P3 <"?#k
int nRead; UWJ8amA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V-2(?auZd
{ Rz:]\jcIT/
nStartPos += fileAccessI.write(b,0,nRead); ,~$p,ALwN7
//if(nThreadID == 1) VUGmi]qd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6|%?tex
} LTCb@L{^i
"]x'PI 4J
@#>rYAb8,
Utility.log("Thread " + nThreadID + " is over!"); oUr66a/[U
bDownOver = true; 1 ~*7f>
//nPos = fileAccessI.write (b,0,nRead); Y;Dp3v!
} ")5":V~fN
catch(Exception e){e.printStackTrace ();} 9C9oUtS
} c?*=|}N
} 7\[@m3s
[z\$?VJspQ
t%FwXaO#
//打印回应的头信息 $am$EU?s
public void logResponseHead(HttpURLConnection con) cN6X#D
{ |\t-g"~sN
for(int i=1;;i++) f:w?pE
{ XS{Qnx_#
String header=con.getHeaderFieldKey(i); JPUW6e07o
if(header!=null) FFpT~.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A#<?4&
Utility.log(header+" : "+con.getHeaderField(header)); IGQFtO/x
else su(1<S}
break; \fdv]f
} : /N0!&7
} >dD@j:Qc
LEf^cM=>
(D&3G;0tK
public void splitterStop() T!kN)#S
{ RJ&RTo
bStop = true; EGS)b
} U&OJXJdj
iByf{I>+
y9GoPC`z
} s`8= 3]w
!hy-L_wL]
gO- _
/* A,<E\
**FileAccess.java uyWunpT
*//文件访问(定位，写) =BAr .m+"
package NetFox; 'KL0@l
import java.io.*; "m8^zg hL
'sKk"bi;0
]:-mbgW
public class FileAccessI implements Serializable{ P|E| $)m
..5CC;B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !i}w~U<
RandomAccessFile oSavedFile; Y\P8v
long nPos; ueWEc^_>
&wawr2)}
4e7-0}0
public FileAccessI() throws IOException {\1?ZrCI&
{ ,w4(kcg%iQ
this("",0); lfgq=8d
} eC4[AX6e
my1@41 H
ec;o\erPG
public FileAccessI(String sName,long nPos) throws IOException +TL%-On
{ !9e=_mY
oSavedFile = new RandomAccessFile(sName,"rw"); iWkWR"ysy
this.nPos = nPos; #:_Kws>+
oSavedFile.seek(nPos); Gb6'n$g
} Q3~H{)[Kq
N>`Aw^ _@&
jB2[(
public synchronized int write(byte[] b,int nStart,int nLen) eo?bL$A[s
{ (5YM?QAd
int n = -1; ^{`exCwMx
try{ 9$w.9`Py
oSavedFile.write(b,nStart,nLen); M|h3Wt~7
n = nLen; <'oQ \eB
} ]%H`_8<gc
catch(IOException e) IEi^kJflU
{ ED gag
e.printStackTrace (); mq.`X:e
} 7n<{tM
r l%
2/^3WY1U
return n; Yj49t_$b
} Lk8ek}o'
g3y~bf
g!|kp?
} J*M>6Q.)
J ZS:MFA
6bC3O4Rw
/* 6H$FhJF
**SiteInfoBean.java 8nV+e~-w
*/ gH{X?
package NetFox; I=N;F6
/zB;1%m-
&}TfJ=gj
public class SiteInfoBean { ;g-L2(T05;
)X8?m <cG
-uho;
private String sSiteURL; //Site's URL r*-e~
private String sFilePath; //Saved File's Path }~8/a3
private String sFileName; //Saved File's Name @B<B#
private int nSplitter; //Count of Splited Downloading File A5d(L4Q]a(
c5>'1L
V}leEf2'
public SiteInfoBean() uO4kCK<7C
{//nSplitter的缺省值为5 |FF"vRi8a7
//default value of nSplitter is 5 ?q}XDc
this("","","",5); Hk65c0
} ~:65e 8K
o6@Hj+,,
N8$MAW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /0w?"2-
{ 3 cd5g
sSiteURL= sURL; 8J&K_JC^
sFilePath = sPath; 9.bMA<X
sFileName = sName; h6!o,qw"
this.nSplitter = nSpiltter; +y+-~;5iv
^7l.!s#$b
i.4L;(cg
} B{ i5UhxD
Z;/"-.i
NW}kvZ
public String getSSiteURL() nN|zEw]
{ &"V%n
return sSiteURL; X%S9H^9
} 8}Pd- .se
bL=32YS
ObDcNq/b!
public void setSSiteURL(String value) "}uPz4
{ jg ~;s
sSiteURL = value; B3 mD0
} ;pU#3e+P8
Sb&sW?M
jV_Eyi3
public String getSFilePath() <{C oM
{ &Wj %`T{
return sFilePath; b"Hg4i)
} dAOmqu,6
N=) E$h
WMB~? EDhv
public void setSFilePath(String value) 5S PGv}if
{ %eoO3"//
sFilePath = value; RH,(8.&>r
} \ H#zRSbZ
M) 9Ss
=bUVGjr%96
public String getSFileName() Pnb?NVP!^9
{ \h6_m)*H4
return sFileName; 5 ^}zysY`
} /*Z,i&eC
mw<LNnT{8
tzv&E0|d
public void setSFileName(String value) A_: Bz:
{ clz6;P
sFileName = value; M*)}F
} qyMR0ai-
Pms"YhyZ7
]}/LNO*L"
public int getNSplitter() c ?mCt0Cg
{ Lwgk}!KR
return nSplitter; wU_e/+0h
} 1F'j.1
>Pv#)qtm
h?2qX
public void setNSplitter(int nCount) |+//pGx
{ :)+|q
nSplitter = nCount; X:\r )
} 6\(wU?m'/
} }p0|.Qu9
#SQao;>
#5)E4"m
/* sHO6y0P
**Utility.java t&(}`W
*/ ,Z*?"d
package NetFox; c@)k#/[[b
2.O;
)sG`sET]`f
public class Utility { ?4wS/_C/
ny17(Y =
-~eNC^t;W
public Utility() A?8f 6
{ zzi%r=%r&
[Y.3miE
> Zo_-,
} ]V J$;v'{[
fkWuSGi
//线程睡眠 aS?A3h4WM_
public static void sleep(int nSecond) xuQ$67F`;z
{ ^R\0<\'
try{ aoQK.7
Thread.sleep(nSecond); hZ!N8nWwNR
} {E!ie{~
catch(Exception e) &Cp)\`[y
{ OOS(YP@b
e.printStackTrace (); QkUq%}_0
} Z8tQ#Pu{
} 0 } uEM_a
.BJ;}
//日志 l)GV&V
public static void log(String sMsg) ^Fgmwa'
{ vK)^;T ;
System.err.println(sMsg); Ko9"mHNB
} 61>@-55k9
eAS~>|N#x
eZR{M\Q
public static void log(int sMsg) }5-^:}gL
{ SU9qF73Y
System.err.println(sMsg); H2`aw3
} L,V\g^4$K
} #rM/
i6M_Gk}
LL@VR#n"V
/* _3DRCNvh
**TestMethod.java G\&4_MS
*/ Q-fi(UP
package NetFox; /PF X1hSu
:a#Mq9ph!
5CH9m[S
public class TestMethod { O0Y/y2d
2i`N26On
`!Ei H<H}
public TestMethod() DZKVZ_q
{ ///xx/weblogic60b2_win.exe 0<75G6wd
try{ ;*ebq'D([
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y}%=:Yt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {^ 1s
SiteFileFetch fileFetch = new SiteFileFetch(bean); CJ0j2e/
fileFetch.start(); YFgQ!\&59
} JTB_-J-TU
catch(Exception e){e.printStackTrace ();} ]@_M)[ x
RGh`=D/yE
I@~hz%'
} N)G.^9
hyv*+FV;
+ew2+2
public static void main(String[] args) bv,_7UOG
{ i~:FlW]
new TestMethod(); @bU(z$eB
} i3g;B?54
} pv1J6
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