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)); lXm]1 *<
} dOqwF iO
for(int i=0;i<nEndPos.length-1;i++) xJ%b<y{@
{ z]\0]i
nEndPos = nStartPos[i+1]; lbg!B4,
} x!!:jL'L
nEndPos[nEndPos.length-1] = nFileLength; 6ssZg@}nf{
} (XT^<#Ga
} VX&KGG.6
+YhTb
O" ['.b
//启动子线程 +S|y)W8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E](Ood
for(int i=0;i<nStartPos.length;i++) w0moC9#$?
{ ep[7#\}5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =g/K>B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !e.@Xk.P6
nStartPos,nEndPos,i); j/wNPB/NM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nb22bXt
fileSplitterFetch.start(); n7X3aoVV
} ?mRU9VY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IcPIOCmOc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $9*Xfb/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L3X>v3CZ5
nEndPos = " + nFileLength); ykl./uY'
// fileSplitterFetch[nPos.length-1].start(); 1NN99^q
"v jFL9
yBauK-7*c
//等待子线程结束 N+!{Bt*
//int count = 0; {:od=\*R
//是否结束while循环 8!me$k&
boolean breakWhile = false; D4n~2]
]Rnr>_>x;
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while(!bStop) ;{BELv-4
{ lGjmw"/C
write_nPos(); Hc^b}A y7
Utility.sleep(500); lh~!cOm\=E
breakWhile = true; 7u\^$25+h
ZxbWgM5rm
v8 ggPI
for(int i=0;i<nStartPos.length;i++) .yQDW]q81G
{ InNuK0@
if(!fileSplitterFetch.bDownOver) uGc}^a2
{ 04:^<n+{
breakWhile = false; K!HSQ,AC
break; 69r<Z
} \|DcWH1
} 292e0cE
if(breakWhile) -`iZBC50
break; 5ah]E
o*I=6`j
2HkP$;lED
//count++; mWUQF"q8
//if(count>4) yWFDGk
// siteStop(); cL<
} lkFv5^%
5cgDHs
%{&yXi:mS
System.err.println("文件下载结束！"); Po(9BRd7
} gAgzM?A1(
catch(Exception e){e.printStackTrace ();} noOG$P#
} @\z2FJ79w
bb+-R_3Kd
>=6tfLQ
//获得文件长度 l>7`D3
public long getFileSize() e<9IwS!/
{ <.s[x~b\`
int nFileLength = -1; vDv:3qN7(
try{ a0CmCv2#
URL url = new URL(siteInfoBean.getSSiteURL()); ArbfA~jXB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cZZ-K?_
httpConnection.setRequestProperty("User-Agent","NetFox"); FuLP{]Y+AM
9'\18_w
:)cPc7$8
int responseCode=httpConnection.getResponseCode(); wC`])z}bT
if(responseCode>=400) -fT]}T6=
{ k[gO>UGB;
processErrorCode(responseCode); l`~*"4|/
return -2; //-2 represent access is error mcpM<vY/H
} c3Y\XzV3v
68+9^
HKb8z@;%@
String sHeader; ^6Hfq^ejt
yFH)PQ_
&#w] 2~|
for(int i=1;;i++) N'i%9SBcg
{ a5:YP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o[O-|XL_
//Utility.log(in.readLine()); F%+/j5~^
sHeader=httpConnection.getHeaderFieldKey(i); 37T<LU
if(sHeader!=null) >j|.pi
{ 9`$fU)K[Pl
if(sHeader.equals("Content-Length")) go@UE2qw
{ ,L6d~>=41
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g"FG7E&
break; /3L1Un*
} #dtYa
} JC_Y#kN@z
else tTLD6#
break; ;Bat!K7W
} C*,-lk0b@
} tUDOL-Tv
catch(IOException e){e.printStackTrace ();} OgY4J|<
catch(Exception e){e.printStackTrace ();} m3+MRy5
fOdkzD,
$[by)
Utility.log(nFileLength); B=jJ+R
0;#%KC,
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return nFileLength; kBS;SDl)
} C;1A$]bk
e>#*$4tg
mawomna
//保存下载信息（文件指针位置） 2+s_*zM-
private void write_nPos() )~rfx
{ |ITp$_S
try{ 4askQV &hj
output = new DataOutputStream(new FileOutputStream(tmpFile)); " 2Dz5L1v
output.writeInt(nStartPos.length); <IC=x(T
for(int i=0;i<nStartPos.length;i++) 26G2. /**<
{ SsIy;l
// output.writeLong(nPos); 1y2D]h/'
output.writeLong(fileSplitterFetch.nStartPos); {Uz@`QO3
output.writeLong(fileSplitterFetch.nEndPos); 9gZMfP
} JN .\{ Y
output.close(); /!=uM.
} TUw^KSa
catch(IOException e){e.printStackTrace ();} u}\F9~W-{
catch(Exception e){e.printStackTrace ();} }/nbv;)
} X};m\Bz
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=!w5%|r.
//读取保存的下载信息（文件指针位置） j&6,%s-M`a
private void read_nPos() mSp-
{ *`mPPts}
try{ zH0%; o}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yM}}mypS
int nCount = input.readInt(); $3[IlQ?
nStartPos = new long[nCount]; WS/^WxRY
nEndPos = new long[nCount]; *p`0dvXG2
for(int i=0;i<nStartPos.length;i++) +iz5%Qe<f
{ 5Q#;4
nStartPos = input.readLong(); Kfa7}f_
nEndPos = input.readLong(); Wb+^Ue
} #=V%S 2~
input.close(); +dX1`%RR[
} 6}='/d-[
catch(IOException e){e.printStackTrace ();} K_{f6c<
catch(Exception e){e.printStackTrace ();} 4v_?i@,L
} m2E$[g
F l83 Z>
/ *RDy!m
private void processErrorCode(int nErrorCode) %6+J]U
{ orVsMT[A
System.err.println("Error Code : " + nErrorCode); }zY)H9J~
} #s$b\"4
1P#bR`I >
1L]7*NJe
//停止文件下载 3~z4#8=
public void siteStop() L>5VnzSI
{ g]EDL<b
bStop = true; lTY%,s
for(int i=0;i<nStartPos.length;i++) +c.A|!-
fileSplitterFetch.splitterStop(); l=8)_z;~D
9uV/G7Geq
\(Dq=UzQI
} l+Dl~o}
} #4%4iR5%
//负责部分文件的抓取 ,],"tzKtE
**FileSplitterFetch.java K QXw~g?
*/ 8 !Pk1P
package NetFox; '(mJ*Eb
pisk v[
(JH LWAH
import java.io.*; l>`N+ pZ$
import java.net.*; R $HIJM
j/4N
)8kcOBG^L
public class FileSplitterFetch extends Thread { }YW0?-G.$
,Dfq%~:grT
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String sURL; //File URL A ${b]
long nStartPos; //File Snippet Start Position kq6S`~J^R
long nEndPos; //File Snippet End Position @[#U_T- I
int nThreadID; //Thread's ID !8yw!hA
boolean bDownOver = false; //Downing is over .F:qJ6E
boolean bStop = false; //Stop identical b#bdz1@s
FileAccessI fileAccessI = null; //File Access interface iDt^4=`
nr*~R-,\
DeE-M"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %lNv?sWb
{ _I8L#4\(=
this.sURL = sURL; W7>4-gk
this.nStartPos = nStart; sP$bp Z}
this.nEndPos = nEnd; W.iL!x.B@
nThreadID = id; R#i|n<x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0@d)DLM?
} xx0s`5
[hTGWT3
Vo}3E]
public void run() A`Q'I$fj
{ '\\dh
while(nStartPos < nEndPos && !bStop) ";E Mu(IXb
{ =]&?(Gq
|={><0
}^Be^a<ub
try{ Nr=ud QA{
URL url = new URL(sURL); ;v'7l>w3\w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .CdaOWM7
httpConnection.setRequestProperty("User-Agent","NetFox"); 4J0{$Xuu0
String sProperty = "bytes="+nStartPos+"-"; mE(EyB<
httpConnection.setRequestProperty("RANGE",sProperty); Y$b4Ga9j
Utility.log(sProperty); Zs<}{`-
Bzn{~&i?W:
jLX{$,
InputStream input = httpConnection.getInputStream(); <8Ek-aNNt
//logResponseHead(httpConnection); xy>wA
Z.Lm[$/edn
_5%SYxF*y
byte[] b = new byte[1024]; s,m+q)
int nRead; Yq}7x1mm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [H;HrwM s)
{ JIvVbI
nStartPos += fileAccessI.write(b,0,nRead); QLH&WF
//if(nThreadID == 1) :'?%%P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qb(#{Sw0
} @'L/]
yaD<jc(O
hDJq:g wD
Utility.log("Thread " + nThreadID + " is over!"); {MdxIp[
bDownOver = true; zIt-mU
//nPos = fileAccessI.write (b,0,nRead); U^vQr%ha
} WXu:mv,'e
catch(Exception e){e.printStackTrace ();} eT1b88_
} `}.K@17
} h=SQ]nV{
}[}u5T`w>
"}Kvx{L8
//打印回应的头信息 2K<rK(
public void logResponseHead(HttpURLConnection con) i)f3\?,,
{ ]'V8{l
for(int i=1;;i++) )tR5JK} AV
{ F>jPr8&
String header=con.getHeaderFieldKey(i); ~t[#p:
if(header!=null) 0}Rxe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \]GO*]CaV
Utility.log(header+" : "+con.getHeaderField(header)); B!GpD@U
else F{)YdqQ
break; +qq,;npi
} 9 tkj:8_
} rHPda?&H
E@TX>M-&
WRU/^g3O@'
public void splitterStop() O%5cMz?eU
{ sv\'XarM
bStop = true; |0FRKD]
} t^ LXGQ
c_c]0Tm
SY|r'8Z%Q
} qJ|ByZ.N+
[1B F8:
J9S9rir&
/* kB1]_v/
**FileAccess.java :khl}|
*//文件访问(定位，写) )V~Fl$A
package NetFox; .z&V!2zp
import java.io.*; m76**X
6g4CUP'Y
*6 -;iT8
public class FileAccessI implements Serializable{ "Pi\I9M3
bcL>S$B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wGa0w*$
RandomAccessFile oSavedFile; R9&T0Qf
long nPos; 3lH#+@
=o\:@I[
u{0+w\xH\
public FileAccessI() throws IOException E{gu39D
{ y_J~n 9R
this("",0); !P/ ]o
} =<fH RX`
H6E@C}cyM
,Hh7'`
public FileAccessI(String sName,long nPos) throws IOException MuB8gSu
{ fZ$<'(t
oSavedFile = new RandomAccessFile(sName,"rw"); hj64ES#x
this.nPos = nPos; GlP [:
oSavedFile.seek(nPos); S_LY>k?
} vb/*ILS
G~_5E]8
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public synchronized int write(byte[] b,int nStart,int nLen) x&sT )=#
{ MK9?81xd
int n = -1; Fn$/ K
try{ _?<Y>B, E
oSavedFile.write(b,nStart,nLen); >0)E\_ u
n = nLen; g0I<Fan
} ^ L'8:
catch(IOException e) K+2bNKZ0
{ Pc{D,/EpR
e.printStackTrace (); lMAmico
} !jY/}M~F1
+4\JY"oi
*LcLYxWo
return n; zr@Bf!VG:
} N%;Q[*d@/
"BjQs<]%sF
dvxD{UH
} /-z_"G
!_E E|#`n
EA7]o.Nm*{
/* wOE_2k
**SiteInfoBean.java 6nt$o)[
*/ /b6Y~YbgU
package NetFox; TFbCJ@X
bL_s[-7
)<G>]IP<
public class SiteInfoBean { d|TRP,y
seY0"ym&e
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private String sSiteURL; //Site's URL d hiLv_/
private String sFilePath; //Saved File's Path yd"|HHx
private String sFileName; //Saved File's Name $m:}{:LDCf
private int nSplitter; //Count of Splited Downloading File ;Fcdjy
7}Z.g9<
^T'+dGU`
public SiteInfoBean() M_MiY|%V/K
{//nSplitter的缺省值为5 mmY~V:,Kd
//default value of nSplitter is 5 JiZ9ly(G
this("","","",5); )ZzwD]
} ]]o7ej
i051qpj
vq$%Ug/B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \F,?ptu
{ ;1S{xd*^N
sSiteURL= sURL; G,{L=xOh
sFilePath = sPath; FU!U{qDI
sFileName = sName; V5KAiG<d
this.nSplitter = nSpiltter; 7qon:]b4
U"-mLv"|
&N0W!
} Mp75L5
@^Mn PM
",E6)r
public String getSSiteURL() #:T5_9p
{ pX6T7
return sSiteURL; d(,-13
} ;knSn$
,!kyrk6
[rTV)JsTb
public void setSSiteURL(String value) i3: sV5
{ ~J)4(411
sSiteURL = value; GY,@jp|R
} [HF)d#A
_+|*
=%Ut&6}sQ
public String getSFilePath() 5 W(iU
{ Ul@ZCv+
return sFilePath; ~/3cQN^
} 1}S_CR4XBs
""Drf=]
1>a^Q
public void setSFilePath(String value) ;}f%bE
{ -2> L*"^
sFilePath = value; Uo^s]H#:
} kKE2~ q
j])iyn~-Ke
!SJmu}OB]
public String getSFileName() cJ]`/YJ
{ CvQ LF9|
return sFileName; 1Od:I}@
} ]*i>KR@G
VmBLNM?
51x^gX|
public void setSFileName(String value) H/)=
{ A ,LAA$
sFileName = value; C+5^[V
} dUb(C1h
L8bq3Q'p
"%f>/k;!h.
public int getNSplitter() OFRzzG@
{ k%In
return nSplitter; JB%6G|Z
} MM'<uy
d/t'N-m
-2 tZ
public void setNSplitter(int nCount) `R:<(:
{ u8o7J(aQsR
nSplitter = nCount; 9\Xl3j!
} 3M1(an\nW
} e1<28g
G>:l(PW:
#Q'i/|g
/* B]*&lRR
**Utility.java gmLw.|-
*/ \Z+v\5nmO
package NetFox; JH)&Ca>S
r4D66tF
_R5^4-Qe
public class Utility { ;F5B)&/B
,\=u(Y\I[
1>1|>%
public Utility() ?erDP8
{ 2lp.Td`{
HNh=igu
;quGy3
} 3ZZJYf=
-w@fd]g
//线程睡眠 PA5g]Tz
public static void sleep(int nSecond) c,D'Hl6(%
{ "{V,(w8Dt
try{ [dzb{M6_
Thread.sleep(nSecond); jNIM1_JjD
} '6/uc:zv
catch(Exception e) ~{5%~8h.0r
{ Fa/i./V2
e.printStackTrace (); jzPC9
} CJu;X[6
} fA3
yS3x))
//日志 Sl$dXB@
public static void log(String sMsg) hM8G"b
{ qQ1m5_OD`z
System.err.println(sMsg); G3U+BC23E
} -y/?w*Cx
[j!0R'T
fptW#_V2
public static void log(int sMsg) iww h,(
{ S[u<vHy
System.err.println(sMsg); C*78ZwZ
} "M:arP5f
} (K?[gI
hh8UKEM-
17 j7j@s)
/* ]&r/H17
**TestMethod.java N{q'wep
*/ r+lY9l
package NetFox; be764do
Eui;2P~
71A{"
public class TestMethod { 4\$Ze0tv
{UUVN/$
}pTj8Tr
public TestMethod() qq?>ulu*W
{ ///xx/weblogic60b2_win.exe }40/GWp<f
try{ _c(=>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l y%**iN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L,D!T&B
SiteFileFetch fileFetch = new SiteFileFetch(bean); kfVG@o?o
fileFetch.start(); Tbwq_3fK
} n>eIQaV
catch(Exception e){e.printStackTrace ();} +}Q4 g]M8
c:$:j,i}
.xk<7^ZD
} q?MYX=Y6
4sJx_Qi
\hq8/6=4s
public static void main(String[] args) \u/5&[;
{ H?~u%b@
new TestMethod(); @qe>ph[UA
} 43)9iDmJ8<
} B{K'"uC
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