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)); }u&JX
} &td#m"wI
for(int i=0;i<nEndPos.length-1;i++) f[RnL#*xJU
{ n*1UNQp@]O
nEndPos = nStartPos[i+1]; m|k,8guG
} :o:??tqw
nEndPos[nEndPos.length-1] = nFileLength; Yem\`; *
} ?,NAihN]
} _e'mG'P(
2S;zze7)
ke0W?
//启动子线程 ".\(A f2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j;3o9!.s:
for(int i=0;i<nStartPos.length;i++) l.BNe)1!22
{ B_S3}g<~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `+uXL9mo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D6t]E)FH
nStartPos,nEndPos,i); 9 2EMDKJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cMv3` $
fileSplitterFetch.start(); `FwAlYJK
} J0 P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8`2K=`]ES+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iCS/~[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dUZ&Ty^{
nEndPos = " + nFileLength); d1-p];&
// fileSplitterFetch[nPos.length-1].start(); A@ME7^w7
?<;<#JN
zvD5i,I
//等待子线程结束 zYL^e @
//int count = 0; \K6J{;#L
//是否结束while循环 gm DC,"Y<
boolean breakWhile = false; s,Swlo7D!
m5Kx}H~
6,PLzZ5
while(!bStop) St`m52V(5X
{ 9o`3g@6z
write_nPos(); ${wE5^ky
Utility.sleep(500); n&]w* (,
breakWhile = true; BXY'%8q _a
keOW{:^i
Vd4osBu{fY
for(int i=0;i<nStartPos.length;i++) $w\, ."y
{ M6iKl
if(!fileSplitterFetch.bDownOver) k:Q<Uanc[
{ |xm|Q(PG
breakWhile = false; I>aa'em
break; B5G$o{WM
} FS:WbFmc
} 3)Y:c2
if(breakWhile) $ *A3p
break; G.8b\E~
=6&D4~R
cmI#R1\
//count++; b`zf&Mn
//if(count>4) 7g9^Jn
// siteStop(); ;kBies>V
} 5g5NTm`=<
t;Om9
R:N-y."La.
System.err.println("文件下载结束！"); ISew]R2
} sfE8b/Z8
catch(Exception e){e.printStackTrace ();} lvi:I+VgA
} avu,o
,~(}lvqVH
$:!T/*p*
//获得文件长度 Bq_P?Q+\
public long getFileSize() Z;D3lbqE
{ -^v}T/Kl#
int nFileLength = -1; C&kl*nO
try{ :'~ gLW>j
URL url = new URL(siteInfoBean.getSSiteURL()); &tCtCk%{j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X>7]g670@
httpConnection.setRequestProperty("User-Agent","NetFox"); J|S^K kC
C}_:K)5q
RI3{>|*
int responseCode=httpConnection.getResponseCode(); W+e*(W|d6
if(responseCode>=400) 4&hqeY3
{ y51D-vj
processErrorCode(responseCode); -i5g 8t'
return -2; //-2 represent access is error 2-!Mao"^
} =@=R)C4f*
\N+Ta:U1P
Gj`Y2X2r
String sHeader; e-3pg?M
i03}f%JnuO
ZM`P~N1?)g
for(int i=1;;i++) )+4}Ix/q
{ %L>nXj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Pl&`&N;
//Utility.log(in.readLine()); '8kjTf#g<l
sHeader=httpConnection.getHeaderFieldKey(i); "UGj4^1f
if(sHeader!=null) #aY<J:Nx
{ #r)1<}_e#
if(sHeader.equals("Content-Length")) ~Z6p3# !o
{ Ny,A#-?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bye@5D
break; tO>OD#
} k5QD5/Ej
} >"g<-!p@
else ivz9R'
break; y{Y+2}Dv/
} A2:){`Mw
} Jo aDX ,
catch(IOException e){e.printStackTrace ();} 7h9[-d6
catch(Exception e){e.printStackTrace ();} 3hf;4Mb
fwv T2G4
6Y_O^f
Utility.log(nFileLength); J*~2:{=%
6+nMH +[
dwbY"t[9
return nFileLength; %^?3s5PXD
} NU&^7[!yl
pebx#}]p-
Y:!/4GF
//保存下载信息（文件指针位置） z5&%T}$tJ
private void write_nPos() tZu*Asx7
{ M|5]#2J_2
try{ 5*wApu{2A
output = new DataOutputStream(new FileOutputStream(tmpFile)); acYoOW1G
output.writeInt(nStartPos.length); i=X*
for(int i=0;i<nStartPos.length;i++) AK s39U'
{ 2u*h*/
// output.writeLong(nPos); [mf7>M`p]@
output.writeLong(fileSplitterFetch.nStartPos); t>6x)2,TC
output.writeLong(fileSplitterFetch.nEndPos); Dj ]Hgg
} (o6[4( G
output.close(); $dZ>bXUw:
} /x:(SR2,
catch(IOException e){e.printStackTrace ();} "gbnLKs
catch(Exception e){e.printStackTrace ();} cbu nq"
} VU`z|nBW@
2 ]DCF
]o[X+;Tj|
//读取保存的下载信息（文件指针位置） %%+mWz a
private void read_nPos() 3$$5Mk(&
{ A eGG
try{ \at-"[.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <nw<v9Z
int nCount = input.readInt(); <=m 30{;f
nStartPos = new long[nCount]; cbh#E)['
nEndPos = new long[nCount]; @!":(@3[
for(int i=0;i<nStartPos.length;i++) bQXc IIa{
{ ;h,R?mU
nStartPos = input.readLong(); OC?Zw@
nEndPos = input.readLong(); zr3q>]oma
} 4j. |Y
input.close(); Esz1uty
} (zS2Ndp
catch(IOException e){e.printStackTrace ();} y|e2j&m
catch(Exception e){e.printStackTrace ();} 4V228>9w
} JtYYT/PB
Wkg*J3O
'NT#(m%
private void processErrorCode(int nErrorCode) L,b|Iq
{ Tsm1C#6 Y*
System.err.println("Error Code : " + nErrorCode); to!mz\F
} ^eaRgNz
nW$A^
Avs7(-L+s
//停止文件下载 Y)Znb;`?a
public void siteStop() C(F1VS
{ fuNl4BU
bStop = true; aQ!9#d_D
for(int i=0;i<nStartPos.length;i++) rV8(ia
fileSplitterFetch.splitterStop(); iO%Zd[
m\*&2Na
b?Cmc
} 1-6gB@cvQ
} ER~T'-YMS
//负责部分文件的抓取 E/wQ+rv
**FileSplitterFetch.java TnN^2:cU
*/ kf+JM/
package NetFox; q4sl=`L5Sp
$xRo<,OV+
6-*~t8
import java.io.*; xZ^ywa_
import java.net.*; QO5OnYh
Jj=yG"$!
f![xn2T
public class FileSplitterFetch extends Thread { b(q$j/~ zb
Nl~Z,hT$*
*oEv,I_
String sURL; //File URL ]{K5zSK
long nStartPos; //File Snippet Start Position ]~?S~l%
long nEndPos; //File Snippet End Position D-Bv(/Pz]$
int nThreadID; //Thread's ID CCuxC9i7
boolean bDownOver = false; //Downing is over ,(j>)g2Ob
boolean bStop = false; //Stop identical gXq!a|eH
FileAccessI fileAccessI = null; //File Access interface 4|zd84g
r> Fec
?@_v,,|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jmRhAJV
{ rU; g0'4e
this.sURL = sURL; IM[54_I
this.nStartPos = nStart; :0nK`$'
this.nEndPos = nEnd; Ezi' 2Sc
nThreadID = id; Vn)%C_-]A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jZa25Z00
} hA@zoIoe
D35m5+=I
jz %;4e~t
public void run() I_:t}3s
{ =8O}t+U
while(nStartPos < nEndPos && !bStop) 40 A&#u9o
{ 86/.8
2y^Uk,g
"=9-i-K9B
try{ cE^kpnVq|<
URL url = new URL(sURL); A)OdQFet(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D._{E*vg
httpConnection.setRequestProperty("User-Agent","NetFox"); l &}piC
String sProperty = "bytes="+nStartPos+"-"; \^yXc*C
httpConnection.setRequestProperty("RANGE",sProperty); IS-}:~Pi
Utility.log(sProperty); \.5F](:
NI^{$QMj
dI!8S
InputStream input = httpConnection.getInputStream(); I9;xzES
//logResponseHead(httpConnection); OSU{8.
1d`cTaQ-
37#cx)p^f
byte[] b = new byte[1024]; =ntftSH
int nRead; hl`u"?rg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QQ*gFP.Ao
{ >Q&CgGpW$
nStartPos += fileAccessI.write(b,0,nRead); : -E,
//if(nThreadID == 1) I[@ts!YD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5;}2[3}[
} H4W1\u
-jFP7tEv
|0lLl^zp
Utility.log("Thread " + nThreadID + " is over!"); g-XKP
bDownOver = true; p*Xix%#6
//nPos = fileAccessI.write (b,0,nRead); *E.LP1xP
} !-7_ +v>
catch(Exception e){e.printStackTrace ();} ]7*kWc2
} ;r3}g"D@
} iZC>)&ax
\/n+j!
_wmI(+_
//打印回应的头信息 2.ew^D#
public void logResponseHead(HttpURLConnection con) Mw+v"l&mU
{ h 5Hr[E1
for(int i=1;;i++) [O(m/
{ |88CBiu}
String header=con.getHeaderFieldKey(i); .wP/ai>}
if(header!=null) Oc#>QZ3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3EI]bmi~
Utility.log(header+" : "+con.getHeaderField(header)); \Y+")
else Y|_O8[
break; JwB"\&'1ZS
} Z/gsCYS3F
} F.68iN}
x7HA722w
S#mK Pi+3
public void splitterStop() p3 e|j
{ f9a$$nb3`
bStop = true; Zb"jB$58
} )(lJT&e
drI\iae{^
IytDvz*|
} TU%bOAKF\
M1EOnq4-
GB=bG%Tb
/* >nK%^T
**FileAccess.java L:pUvcAc?
*//文件访问(定位，写) Q(e{~ ]*
package NetFox; x)_r@l`$ix
import java.io.*; J+|/-{g
V9Hl1\j^
}vY.EEy!
public class FileAccessI implements Serializable{ O@wK[(w^
AuXs B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5B?i(2&#
RandomAccessFile oSavedFile; !3V{2-y$-
long nPos; *{|$FQnR>(
'60//"9>k/
m]P/if7
public FileAccessI() throws IOException ?A&%Cwj
{ vY_eDJ~'
this("",0); bcn7,ht
} '%&z.{
;{gT=,KQ`
, D"]y~~I5
public FileAccessI(String sName,long nPos) throws IOException *VDVC0R
{ =k_UjwgN^
oSavedFile = new RandomAccessFile(sName,"rw"); G?ig1PB"#
this.nPos = nPos; ?-,6<K1
oSavedFile.seek(nPos); ({ k7#1 h8
} yLqF ,pvO
i?-Y
`*k@4.J{
public synchronized int write(byte[] b,int nStart,int nLen) (:7a&2/M
{ vBoO'l9'M
int n = -1; CN\=9Rvs
try{ oM-[B h]A
oSavedFile.write(b,nStart,nLen); `tVy_/3(9
n = nLen; U=QA e
} Ww`&i
catch(IOException e) v2>Z^
{ BIj
e.printStackTrace (); nNQ-"t
} &d,Wy"WPi
`0@z"D5c
zJCEA
return n; fGarUV
} iRve)
b-%l-u
gDC2 >nV
} Q0>q:aj\
(a#pvEY
ArXl=s';s4
/* onnugj3
**SiteInfoBean.java 5@f5S0 Y
*/ mb{q(WEPP
package NetFox; \fi}Q\|C
d.r Y-k
0*yJ %
public class SiteInfoBean { doLNz4W
niWx^gKb$
,YB1 y)x
private String sSiteURL; //Site's URL eY}V9*.v
private String sFilePath; //Saved File's Path @i1q]0
private String sFileName; //Saved File's Name fp;a5||5
private int nSplitter; //Count of Splited Downloading File V^rW?Do
]sL45k2W
s|2}2<+
public SiteInfoBean() |GuEGmR
{//nSplitter的缺省值为5 GOVAb'
//default value of nSplitter is 5 2w4MJ,Uw
this("","","",5); Gru ALx7
} F,pCR7o>
i0ybJOa4
$E.XOpl&I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +)gB9DoK
{ }N,>A-P
sSiteURL= sURL; m =k%,J_
sFilePath = sPath; (oYW]c}G,
sFileName = sName; 6N3@!xtpi
this.nSplitter = nSpiltter; '{VM>Q
GYoseqZM
[hnK/4!
} w~N-W8xNR
<'2u a
GAp!nix6h
public String getSSiteURL() _9kIRmT{
{ 784;]wdy\
return sSiteURL; YoAg
} ikHOqJ-,m
98UlNP
)4uq iA6
public void setSSiteURL(String value) N-%#\rPq.
{ !01i%W'
sSiteURL = value; , N 344y
} d?7BxYaa
%6i=lyH-
rPO}6lsc
public String getSFilePath() C3.=GRg~l
{ 4B$bj`h
return sFilePath; .bfST.OA
} 6"%2,`Nu
voh^|(:(TH
>'Hx1;
public void setSFilePath(String value) or.\)(m#(
{ 7K:FeW'N
sFilePath = value; bQ.nFa']
} xwOE+
Q|//Z
P` ]ps?l
public String getSFileName() a}yR p
{ 4J8Dh;a`
return sFileName; q+%!<]7X
} "TFwHe3C4
v,0<9!'v
OG}KqG!n
public void setSFileName(String value) 6[+j'pW?
{ ^ZVOql&
sFileName = value; ^A#x<J+
} 8&?p
{(0Id!
)_Iz>)
public int getNSplitter() -TZ^~s
{ ?i%nMlcc
return nSplitter; d?}hCo=/Xq
} }.t^D|
2Fq=jOA)z$
8]]@S"ZM,\
public void setNSplitter(int nCount) pN+I]NgQ
{ H &fTh
nSplitter = nCount; %omu
} |0]YA
} 453 }S
K1-+A2snhV
WL/5 oj
/* vX 1W@s
**Utility.java nF|Oy0
*/ 9C=~1>S
package NetFox; |?yE^$a
g/B\ObY
-)>(8f
public class Utility { J@gm@ jLc
$>![wZ3
F {/>u(@3
public Utility() yWmrdvL
{ Cy6%S).c
6"%@L{UQ
y:C)%cv}*
} l-cW;b~
?0uOR*y'
//线程睡眠 R~$hWu}}
public static void sleep(int nSecond) {x9j_/R
{ F$[)Bd/"
try{ %6N)G!P
Thread.sleep(nSecond); *h:D|4oJ(
} ,!r@9T
catch(Exception e) <5M_EJp
{ 9QC< E|
e.printStackTrace (); \FVNXUMU
} p1klLX
} ma1(EJ/
Etw~*
//日志 $,.3&zsy
public static void log(String sMsg) zUJx&5/
{ 0u>yT?jP
System.err.println(sMsg); \|blRm;
} Qg[heND
UmYD]
b-2pzcK{#
public static void log(int sMsg) bBy'v/
{ 1k$2LQ
System.err.println(sMsg); ccRlql(
} ";756'>
} 0T(O'v}.
@51z-T
vf6`s\6
/* NWw<B3aL
**TestMethod.java 15o9CaQw4"
*/ yq1Gqbh l
package NetFox; EK^JLvyT
eR7qE) h
L7X7Zt8%
public class TestMethod { n'q aR<bY
>y]?MGk
H3!,d`D.N
public TestMethod() o1 jk=
{ ///xx/weblogic60b2_win.exe 3Wjq>\
try{ n; Lo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kZJt~}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T@B"BoKU
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]^Sd9ba
fileFetch.start(); k&WUv0
} cR,'o'V/
catch(Exception e){e.printStackTrace ();} ~&t!$
+G<}JJ'V
-b@v0%Q2M*
} z`c%?_EK
_TtX`b_Z
2O?Vr" A
public static void main(String[] args) $5ZR[\$
{ xylpiSJ
new TestMethod(); jn.R.}TT
} 98X!uh'
} 1[26w_B3
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