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)); \2h!aRWR
} M!o##* *`
for(int i=0;i<nEndPos.length-1;i++) a^I\ /&aw'
{ VXwU?_4J.
nEndPos = nStartPos[i+1]; #"G]ke1l$
} rbWP78
nEndPos[nEndPos.length-1] = nFileLength; -Ps!LI{@
} *_d7E
} X9V*UXTc
;>Ib^ov
@J/K-.r
//启动子线程 XwJ7|cB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )AvN\sC
for(int i=0;i<nStartPos.length;i++) ?Wlb3;
{ 3ca (i/c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {ttysQ-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [DI+~F
nStartPos,nEndPos,i); ?82xdpg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >G25m'&,7
fileSplitterFetch.start(); =%TWX[w
} 9dx/hFA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rD3v$B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <eWf<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^'PWI{ O
nEndPos = " + nFileLength); xqu}cz
// fileSplitterFetch[nPos.length-1].start(); K &N
{'NvG
cQ R]le%(
//等待子线程结束 ]>5/PD,wWy
//int count = 0; s;ls qQk
//是否结束while循环 vg32y /l]S
boolean breakWhile = false; :74y!
u0`S5?
T4Pgbop
while(!bStop) {8W'%\!=
{ m;GCc8
write_nPos(); )"7iJb<E
Utility.sleep(500); ?^al9D[:lz
breakWhile = true; Pd_U7&w,5
!Dn,^
at,XB.}Z]
for(int i=0;i<nStartPos.length;i++) p8Qk'F=h
{ SE1=>S%p
if(!fileSplitterFetch.bDownOver) vdc\R?
{ ek*rp`y]
breakWhile = false; x??+~$}\*-
break; |ATvS2
} +%h8r5o1
} c(xrP/yOwi
if(breakWhile) Ng2twfSl$
break; \@c,3
52Z2]T c,
LTQ"8
//count++; &]|?o_p3W
//if(count>4) iu=7O
// siteStop(); mn"G_I
} 8e1UmM[
2*laAB
vXrx{5gz
System.err.println("文件下载结束！"); (c=6yV@
} / *#r`A
catch(Exception e){e.printStackTrace ();} - M4JJV(
} dO! kk"qn
^BikV
*av<E
//获得文件长度 E Nhl&J
public long getFileSize() Q{>+ft U
{ -b9\=U[
int nFileLength = -1; @=}0`bE
try{ SJn;{X>)q
URL url = new URL(siteInfoBean.getSSiteURL()); [}E='m}u9+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /[ 5gX^A
httpConnection.setRequestProperty("User-Agent","NetFox"); On9A U:\
m$>H u@Va
Rq'S>#e
int responseCode=httpConnection.getResponseCode(); PR#exm&
if(responseCode>=400) nv|NQ Tk
{ 7rc0yB
processErrorCode(responseCode); X9W@&zQ
return -2; //-2 represent access is error ]8_NZHld
} -P$PAg5"2
8mvy\l EEH
K7_UP&`=J
String sHeader; BU/"rv"(Fg
ohGJ1
_7Ju
for(int i=1;;i++) 4yy>jXDG
{ dd%6t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JE"x
//Utility.log(in.readLine()); q$d>(vbq
sHeader=httpConnection.getHeaderFieldKey(i); AUG#_HE]k
if(sHeader!=null) c<:-T
{ t6"%3#s
if(sHeader.equals("Content-Length")) r= `Jn6@
{ ^1I19q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |.: q
break; [6Izlh+D
} q_[o"wq/
} ]nn98y+
else %D{6[8
break; i &nSh ]KK
} iy.p n
} G"qvz{*
catch(IOException e){e.printStackTrace ();} {L{o]Ii?g
catch(Exception e){e.printStackTrace ();} _}Ac n$
HmGWht6R
oq Xg
Utility.log(nFileLength); Ju@c~Xm
EHJ.T~X
g*AWE,%=|
return nFileLength; *aM=Z+
} ,q`\\d
Xx~Bp+
jp%S3)
//保存下载信息（文件指针位置） `KoV_2|
private void write_nPos() ~^:A{/
{ T4Uev*A
try{ <44G]eb
output = new DataOutputStream(new FileOutputStream(tmpFile)); hD 82tr
output.writeInt(nStartPos.length); oWT3apGO
for(int i=0;i<nStartPos.length;i++) *w`sM%]Rq
{ Z"xvh81P
// output.writeLong(nPos); 2*& ^v
output.writeLong(fileSplitterFetch.nStartPos); vm8eZG|
output.writeLong(fileSplitterFetch.nEndPos); ?(1y
} `g=J%p
output.close(); |mfvr*7
} -$ls(oot
catch(IOException e){e.printStackTrace ();} 4SxX3Fw
catch(Exception e){e.printStackTrace ();} q"lSZ; 'E
} <dtGK~_
+5*95-;0
>1Ibc=}g
//读取保存的下载信息（文件指针位置） V~3a!-m\
private void read_nPos() N#_H6TfMG
{ L,/%f<wd
try{ L~OvY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b{&)6M)zo
int nCount = input.readInt(); M'O <h
nStartPos = new long[nCount]; pz}.9 yI8
nEndPos = new long[nCount]; %YscBG
for(int i=0;i<nStartPos.length;i++) Czu9o;xr
{ )qw&%sO +
nStartPos = input.readLong(); CY5Z{qiX
nEndPos = input.readLong(); EI%89i`3^
} A}9`S6@@
input.close(); K($Npuu]
} (y~TL*B
catch(IOException e){e.printStackTrace ();} mO7]9p
catch(Exception e){e.printStackTrace ();} WSB0~+
} $Ds2>G4c
B~ GbF*j
77f9(~ZnT
private void processErrorCode(int nErrorCode) N=}A Z{$
{ U%QI a TN*
System.err.println("Error Code : " + nErrorCode); zwjgE6
} [}=B8#Jl-C
![=yi tB
f}P3O3Yv&
//停止文件下载 !*N@ZL&X
public void siteStop() 4Z&lYLq;
{ F^;ez/Gl
bStop = true; gR;i(81U
for(int i=0;i<nStartPos.length;i++) X.{S*E:$u
fileSplitterFetch.splitterStop(); \~$#1D1f
N~)_DjQP5
ea 'D td
} SY\ gXO8k
} ",; H`V
//负责部分文件的抓取 ~B?y{
**FileSplitterFetch.java qo bc<-
*/ Ve; n}mJ?
package NetFox; kdeWip6Y
(hbyEQhF
*^ZV8c}
import java.io.*; m-#2n? z-
import java.net.*; VU3upy<
`Ggbi4),
JK5gQ3C[
public class FileSplitterFetch extends Thread { ZBp/sm
%dVZ0dl
H<,gU`&R
String sURL; //File URL $'M!HJxb
long nStartPos; //File Snippet Start Position iqWQ!r^
long nEndPos; //File Snippet End Position on`3&0,.
int nThreadID; //Thread's ID 6LIJQ
boolean bDownOver = false; //Downing is over m;QMQeGz
boolean bStop = false; //Stop identical hz@bW2S.
FileAccessI fileAccessI = null; //File Access interface E ~<JC"]
rjYJs*#
G_,jgg7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >|UOz&
{ %IWPM"
this.sURL = sURL; 2FJ*f/
this.nStartPos = nStart; Tyx_/pJT
this.nEndPos = nEnd; 3f{3NzN
nThreadID = id; lt8|9"9<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @Jw-8Q{
} SE %pw9
kt:! 7
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public void run() EaN6^S=
{ s2'h
while(nStartPos < nEndPos && !bStop) -[.[>&`/
{ u'BaKWPS
4|?;TE5
1=V-V<
try{ h2d(?vOT
URL url = new URL(sURL); xwo<' xT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MQ8J<A Pf-
httpConnection.setRequestProperty("User-Agent","NetFox"); $ddCTS^
String sProperty = "bytes="+nStartPos+"-"; $xN|5;+
httpConnection.setRequestProperty("RANGE",sProperty); fNFY$:4X
Utility.log(sProperty); }pkzH'$HJ
C~/a-
J)-x!y>
InputStream input = httpConnection.getInputStream(); Sdryol<
//logResponseHead(httpConnection); $=4QO
0L52#;?Si"
]c'A%:f<
byte[] b = new byte[1024]; C?eH]hkZ3
int nRead; <Q3c[ Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .$vK&k
{ 7qS)c}Q\
nStartPos += fileAccessI.write(b,0,nRead); Y}wyw8g/
//if(nThreadID == 1) oUlVI*~ND
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A*BeR0(
} Cw&KVw*
H qx-;F~0
xJ.M;SF4
Utility.log("Thread " + nThreadID + " is over!"); utV_W&
bDownOver = true; IH+|}z4N?>
//nPos = fileAccessI.write (b,0,nRead); + {'.7#
} x[e<} 8'$(
catch(Exception e){e.printStackTrace ();} =rdV ]{Wc
} Zj'9rXhrM1
} Z *x'+X
CpTjJXb
l.M0`Cn-%
//打印回应的头信息 U 6)#}
public void logResponseHead(HttpURLConnection con) h/Y'<:
{ LrpM\}t
for(int i=1;;i++) scV5PUq
{ |2A:eI8 ^
String header=con.getHeaderFieldKey(i); SOIN']L|V[
if(header!=null) do'GlU oMC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'LDQgC*%
Utility.log(header+" : "+con.getHeaderField(header)); <N~K;n v
else 4#Jg9o
break; A@#E@;lm
} p6S8VA
} =Dj#gV
"\yT7?},
2GG2jky{/
public void splitterStop() TWX.D`W
{ =?8@#]G+
bStop = true; 2&cT~ZX&'
} ftSW (og
v`T c}c '
Zv{'MIv&v
} wC'Szni
#KvlYZ+1
CWKm(@"5
/* (/$^uWj
**FileAccess.java {P-):
*//文件访问(定位，写) 1|=A*T-<M
package NetFox; |Y.?_lC
import java.io.*; {M)Nnst"~
0=$T\(0g
h{qgEIk&
public class FileAccessI implements Serializable{ +b6v!7_
yB!dp;gM{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |I=T@1_D
RandomAccessFile oSavedFile; +kD R.E:
long nPos; `WS&rmq&'
v"0J&7!J
DHRlWQox
public FileAccessI() throws IOException * v#o
{ ;kKyksxlD
this("",0); dc'Y`e
} m4Zk\,1m.|
-nwypu
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public FileAccessI(String sName,long nPos) throws IOException %"-5 <6d
{ %z$#6?OK^
oSavedFile = new RandomAccessFile(sName,"rw"); !()Qm,1u
this.nPos = nPos; ;9#KeA _
oSavedFile.seek(nPos); J .<F"r>
} |V(0GB
yt2PU_),
6L~n.5B~o
public synchronized int write(byte[] b,int nStart,int nLen) 4^d?D!j
{ 0*v2y*2V
int n = -1; XK vi=0B
try{ $:^td/p J
oSavedFile.write(b,nStart,nLen); ,#K'PB4E
n = nLen; [D1Up
} 19] E 5'AI
catch(IOException e) ee=D1qNu;
{ +w~oH=
e.printStackTrace (); Uw:"n]G]D?
} 0+8e,
|vC~HJpuv'
Pzem{y7Ir
return n; 1 -b_~DF
} %l%HHT
K)P%;X
!@"OB~
} rZpXPI
QsW/X0YBv
Fj!U|l\_9
/* H;"4C8K7
**SiteInfoBean.java !`r$"}g
*/ ajpXL
package NetFox; 8?C5L8)
47B&s
5-A\9UC*@
public class SiteInfoBean { _VXN#@y
"gwSJ~:ds
*K;~!P
private String sSiteURL; //Site's URL -n;}n:wL
private String sFilePath; //Saved File's Path WY]s |2a
private String sFileName; //Saved File's Name d"Y{UE
private int nSplitter; //Count of Splited Downloading File yCo.cd-
d d;T-wa}
%jM,W}2
public SiteInfoBean() LH6vLuf
{//nSplitter的缺省值为5 }PpUAt~g
//default value of nSplitter is 5 T^q 0'#/
this("","","",5); L:x-%m%w
} :E?V.
g\AY|;T
M3Kfd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b`_Q8 J
{ j+YJbL v
sSiteURL= sURL; ,z?':TZ
sFilePath = sPath; #fM'>$N
sFileName = sName; ,u!sjx
this.nSplitter = nSpiltter; B/C,.?Or
-F>jIgeC2v
I}Q2Vu<
} T9&1VW
3uMy]HUQ
DTs;{c
public String getSSiteURL() }~q5w{_n
{ ']oQ]Yx0
return sSiteURL; w*Ihk)
} {>;R?TG]$
L0]_X#s>#
&.ACd+Cd
public void setSSiteURL(String value) <-0]i_4sK
{ 92-I~ !d
sSiteURL = value; WPDyu.QD
} A)KZa"EX
0BsYavCR
2TuU2 f.
public String getSFilePath() y> (w\K9W
{ xLn%hxm?,
return sFilePath; H[|~/0?K
} d!{r v
Dhv3jg;lq
B1Oq!k
public void setSFilePath(String value) \[nut;
{ =Runf +}
sFilePath = value; |&jXp%4T
} Rva$IX^]
YoE3<[KD(
JN6B~ZNf
public String getSFileName() 'm9` 12H
{ uVU)d1N
return sFileName; rQ9'bCSr%
} P>6{&(
k_R"CKd
`,0}ZzaV&
public void setSFileName(String value) tI{_y
{ @lt#Nz
sFileName = value; 1nOCQ\$l
} /Q )\+
|Ds=)S" K
A(N4N
public int getNSplitter() 1&$ nVQ
{ +^<](z
return nSplitter; cGD(.=
} \C1nZk?3
,=N.FS
$7uA%|\
public void setNSplitter(int nCount) HorDNRyu
{ p<;0g9,1
nSplitter = nCount; #D|p2L$
} |)G<,FJQE_
} Xry47a )
%07SFu#
l@:0e]8|o
/* $mB;K]m
**Utility.java PxE3K-S)G
*/ Lh<).<S
package NetFox; 6aV_@no.C
hpJ-r
PYzvCf`?
public class Utility { &VcV$8k
]+$?u&0?w
[trwBZ^D~
public Utility() bJ;'`sw1
{ ;UP$yM;
E.>4C[O
2Hv+W-6v
} yiI1x*^
>"<Wjr8W!$
//线程睡眠 3yXY.>'
public static void sleep(int nSecond) EZ`{Wnbq
{ RX5dO%
try{ s|ITsz0,td
Thread.sleep(nSecond); b_):MQ1{
} xP,hTE
catch(Exception e) jNy.Y8E&
{ V470C@
e.printStackTrace (); 5PnDN\
} <d_!mKw
} @OHm#`~
H7j0K~U0
//日志 4a]P7fx-
public static void log(String sMsg) &! ?eL
{ <"|,"hA
System.err.println(sMsg); GM<-&s!Uj
} b%5f&N
OBAi2Vw
&8 x-o,
public static void log(int sMsg) yvYad
{ K96<M);:g
System.err.println(sMsg); (!N|Kl
} JO<wU
} ?I@W:#>o
bY0|N[g
o0vUj
/* _ORvo{[:
**TestMethod.java ;d9QAN&0}
*/ '08=yqy4N
package NetFox; I 2|Bg,e
^v`\x5"Vp
W{gb:^;zb
public class TestMethod { 6i~WcAs
Ez=Olbk
# 4PVVu<
public TestMethod() &pp|U}
{ ///xx/weblogic60b2_win.exe :[!j?)%>
try{ ]P?vdgEM&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C 6AUNRpl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z/;aT -N
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nu7 !8[?r*
fileFetch.start(); w*JGUk
} 9p2&)kb6
catch(Exception e){e.printStackTrace ();} cjIh}:|'
{,~3.5u
6f*CvW
} & 9 ?\b7
w)Qp?k d
j^2wb+`
public static void main(String[] args) /RC7"QzL
{ qeZ? 7#Gf
new TestMethod(); 46&/gehr
} NPe%F+X
} 4Wm@W E
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