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)); WDI3*
} FqZD'Uu7
for(int i=0;i<nEndPos.length-1;i++) 0ybMI+*
{ BoXPX2:
nEndPos = nStartPos[i+1]; Ej $.x6:
} U8{^-#(Uz
nEndPos[nEndPos.length-1] = nFileLength; Wcbm,O4u
} drvz [ 9;
} )-m/(-
,#bT
j$<g8Bg=o
//启动子线程 85q!FpuH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '|}H,I{
for(int i=0;i<nStartPos.length;i++) 5&.I9}[)j
{ dt0(04
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l,5isq ;m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E5?$=cL?
nStartPos,nEndPos,i); dXPTW;w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e5D\m g)
fileSplitterFetch.start(); Wngc(+6O&
} eM]>"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cfPp>EK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k(xB%>ns
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %XQJ!sC`
nEndPos = " + nFileLength); {8 &=t8,c
// fileSplitterFetch[nPos.length-1].start(); vXZ )
(G~ME>
/i
//等待子线程结束 \~r_S
//int count = 0; ps^["3e
//是否结束while循环 *uSlp_;kB
boolean breakWhile = false; ZENblh8fs
OnyAM{$g
T+PERz(
while(!bStop) `4e| I.`^r
{ Y5y7ONcn
write_nPos(); ix38|G9U
Utility.sleep(500); qeC^e}h
breakWhile = true; oN)I3wO$
EN__C$
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for(int i=0;i<nStartPos.length;i++) fm$Qd^E|e
{ !^EA}N.u
if(!fileSplitterFetch.bDownOver) Ffd4c
{ w]fVELU
breakWhile = false; %.wx]:o
break; B 74
} MShcZtN
} %q.5;L
if(breakWhile) |[p]]) o
break; B`w8d[cL7
_Ea1;dJmq
IpM"k)HR
//count++; gB>AYL%o=
//if(count>4) iVo-z#
// siteStop(); lk`|u$KPz
} 8bf@<VTO_
E&Zt<pRf;2
fl40jo]
System.err.println("文件下载结束！"); dA<SVk*0Q
} .J=QWfqt
catch(Exception e){e.printStackTrace ();} <tm=
} +jS<n13T
DHbS=Iih
n<F3&2w
//获得文件长度 ItVVI"-
public long getFileSize() E>:#{%
{ 'e6J&X
int nFileLength = -1; =BbXSwv'(
try{ 8Pva]Q
URL url = new URL(siteInfoBean.getSSiteURL()); O]?\<&y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5k?xBk=<
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Q0/kG
VCT1GsnE
+U>Y.YP
int responseCode=httpConnection.getResponseCode(); \w&R`;b8w
if(responseCode>=400) Iu(]i?Y
{ @LY[kt6o
processErrorCode(responseCode); lv~ga2>z
return -2; //-2 represent access is error tv2k&\1
} C+_UIx]A
?0-3J )kW
)TBm?VMe
String sHeader; y3bL\d1
+Y2D @K?)
\?|^w.
for(int i=1;;i++) 0g Hd{H=
{ Zqv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yTNHM_P
//Utility.log(in.readLine()); B,` `2\B
sHeader=httpConnection.getHeaderFieldKey(i); N7GZ'-t^Er
if(sHeader!=null) HdTB[(
{ 3Vk\iJ
if(sHeader.equals("Content-Length")) -~*kAh
{ !Q,Dzv"7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A<(Fn_&W
break; /(9.Fqe(
} "*S_wN%
} &x4*YMh
else fo<nk|i
break; TkIiO>
} E 0OHl
} jw/@]f;N
catch(IOException e){e.printStackTrace ();} =>&~p\Aw
catch(Exception e){e.printStackTrace ();} QyrB"_dm
*|cs_,3
o#D'"Tn!
Utility.log(nFileLength); l\2"u M#7
+i}uRO
IR&b2FTcU
return nFileLength; 6BZi4:PDx
} L+mHeS l
#KuBEHr
:bCswgd[
//保存下载信息（文件指针位置） T hVq5
private void write_nPos() &V%faa1
{ z uo:yaO
try{ B`vC>
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1_8@yO
output.writeInt(nStartPos.length); AmUH]+5KT
for(int i=0;i<nStartPos.length;i++) MM&qLAa"f
{ M+)ENve
// output.writeLong(nPos); K_;?Sr=
output.writeLong(fileSplitterFetch.nStartPos); [<}W S} .
output.writeLong(fileSplitterFetch.nEndPos); zFY$^Oz"_
} hVCxwTg^X
output.close(); Yf1%7+V35
} =tX"aCW~
catch(IOException e){e.printStackTrace ();} QVmJ_WT
catch(Exception e){e.printStackTrace ();} 'oM=ZU8wo
} ,,g: x
m!(dk]
67||wh.BU
//读取保存的下载信息（文件指针位置） umpa!q};
private void read_nPos() ]w]:9w
{ YllW2g:
try{ 1M?Sl?+j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gQeoCBCE
int nCount = input.readInt(); #UvWS
nStartPos = new long[nCount]; j*~z.Q|
nEndPos = new long[nCount]; 2ppJ;P{k
for(int i=0;i<nStartPos.length;i++) 4F!%mMq
{ <2LUq@Pg
nStartPos = input.readLong(); > lI2r}
nEndPos = input.readLong(); yb\!4ml
} ^a|
input.close(); 0&3zBL%Bo
} -AQ 7Bd
catch(IOException e){e.printStackTrace ();} M(ie1Ju
catch(Exception e){e.printStackTrace ();} d7Z$/ $
} I]Z"?T
2Y;iqR
M{=p0?X
private void processErrorCode(int nErrorCode) &$h#9
{ {>Qs+]
System.err.println("Error Code : " + nErrorCode); COxJ,v(
} vCtnjWGX}/
\.F|c
;Wn0-`_1,
//停止文件下载 q1A0-W#4
public void siteStop() bOr6"nn
{ hy3?.
bStop = true; I@1VX5
for(int i=0;i<nStartPos.length;i++) yJ(ITJE_Z
fileSplitterFetch.splitterStop(); H.O&seY
y#nyH0U
Nig)!4CG
} 7!e kINQ
} /g!X[rn7Q
//负责部分文件的抓取 !1<>][F
**FileSplitterFetch.java JP]-a!5Ru
*/ c=Zurqj
package NetFox; m'2EiYX$}\
)-i(%;,*e
#BI6+rfv|
import java.io.*; , lBHA+@
import java.net.*; h0l_9uI
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public class FileSplitterFetch extends Thread { %.:]4jhk
iP?lP= M
i}C%`1+(
String sURL; //File URL Qs 'dwc
long nStartPos; //File Snippet Start Position 9"dZ4{\!
long nEndPos; //File Snippet End Position //#]CsFiP
int nThreadID; //Thread's ID OV-#8RXJ
boolean bDownOver = false; //Downing is over F[X;A\
boolean bStop = false; //Stop identical ALKzR433/
FileAccessI fileAccessI = null; //File Access interface >6'brb
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T 0?9F2
{ (V`ddP-
this.sURL = sURL; ~b9fk)z!
this.nStartPos = nStart; .zJZ*\2ob
this.nEndPos = nEnd; WwLV^m]
nThreadID = id; &Z+.FTo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9n3.Ar
} djDE0-QxcR
g7K<"Z {M
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public void run() Z}>+!Z
{ )2bbG4:N
while(nStartPos < nEndPos && !bStop) >UV=k :Q
{ B\>3[_n
0fa8.g#I$
}G<A$*L1
try{ :(4];Va
URL url = new URL(sURL); i6k~j%0m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o H]FT{
httpConnection.setRequestProperty("User-Agent","NetFox"); sP%J`L@h
String sProperty = "bytes="+nStartPos+"-"; eS2VLVxu
httpConnection.setRequestProperty("RANGE",sProperty); wOR#sp&
Utility.log(sProperty); FNXVd/{M3
^;cJjl'=
Kxsj_^&|i
InputStream input = httpConnection.getInputStream(); K$-|7tJon
//logResponseHead(httpConnection); 22D,,nC0+=
.U,>Qn4/
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byte[] b = new byte[1024]; ZIaFvm&q7Z
int nRead; ?M04 cvm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :a M@"#F
{ nY?X@avo>
nStartPos += fileAccessI.write(b,0,nRead); n:%A4*
//if(nThreadID == 1) m8&XW2S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AKAxfnaR
} SXmh@a"*\
K(}<L-cv
ns&(g^
Utility.log("Thread " + nThreadID + " is over!"); `u7twW*U2
bDownOver = true; t\lx*_lr
//nPos = fileAccessI.write (b,0,nRead); 7 '7a`-W
} RH;Kbu
catch(Exception e){e.printStackTrace ();} !)uXCg9U
} D o!]t7Y$
} Q8bn|#`
+fq;o8q
Y67i\U>?
//打印回应的头信息 )h;zH,DA[3
public void logResponseHead(HttpURLConnection con) &0J/V>k
{ (9!kKMQW'
for(int i=1;;i++) x_x|D|@wM
{ 9q"G g?
String header=con.getHeaderFieldKey(i); O9)k)A]`O
if(header!=null) *9}~?#b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s9BdmD^|#
Utility.log(header+" : "+con.getHeaderField(header)); _P{v=`]Eu
else f{#Mc
break; ,CnUQx0
} ^4>Icz^ F
} \J^xpR_0u
V;]U]
20mZ{_%
public void splitterStop() jp-]];:aPJ
{ Ji:0J},m
bStop = true; }/Y)^
} 8?k.4{?
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8j!(*'J.
} p9iCrqi
"C [uz&
]\:l><
/* PX,fg5s\b
**FileAccess.java Re'Ek
*//文件访问(定位，写) '>|5
package NetFox; c# WIB 4
import java.io.*; )hK1W\5
4(\7Or(''
tqK}KL
public class FileAccessI implements Serializable{ 7.xJ:r|
R)qK{wq(1E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DZ0\pp?S
RandomAccessFile oSavedFile; " qrL:,
long nPos; %b`B.A
4$b9<:M_
.@]M'S^1
public FileAccessI() throws IOException ^b(>Bg)T
{ }@wXm
this("",0); DR#[\RzNI
} gc{5/U9H*
DX#F]8bWl
%q,^A+=
public FileAccessI(String sName,long nPos) throws IOException j~rarR@NB)
{ >eaK@u-'0
oSavedFile = new RandomAccessFile(sName,"rw"); g].hL
this.nPos = nPos; =;A~$[g
oSavedFile.seek(nPos); ~b{j`T
} u+uu?.bM
auQfWO[ u
vW4N[ .+
public synchronized int write(byte[] b,int nStart,int nLen) \Rvsy;7
{ Bn{0-5nj
int n = -1; ?GKm_b]JC
try{ 6u v'{
oSavedFile.write(b,nStart,nLen); yj{:%Km:`
n = nLen; 98eS f
} MHKB:t]hA
catch(IOException e) q CB9z
{ mPo].z
e.printStackTrace (); _a=f.I
} \78kShx
T?E[LzZg
R|H_F#eVn}
return n; \:wLUGFl5
} \ g[A{
6WnGP>tc.
3$ 1 z
} '$n#~/#}
>jDx-H.N
S=~8nr/V
/* %;9+`U
**SiteInfoBean.java r#[YBaCZJ
*/ OHha5n
package NetFox; wY j~(P"
7oI^shk
OT5'cl
public class SiteInfoBean { BV HO_
2nPU $\du
}ZWeb#\
private String sSiteURL; //Site's URL o(@F37r{?
private String sFilePath; //Saved File's Path l?%U*~*
private String sFileName; //Saved File's Name !Rw\k'<GKX
private int nSplitter; //Count of Splited Downloading File wc'K=;c
lCyp&b#(L
~X -.@k'
public SiteInfoBean() ZVek`Cc2
{//nSplitter的缺省值为5 dO[w3\~
//default value of nSplitter is 5 lC i_G3C
this("","","",5); I"=XM
} /aB9pD+%
O}3M+
%7?v='s=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OAQ'/{~7
{ ,FPgbs
sSiteURL= sURL; +>5 "fs$Y
sFilePath = sPath; VSkx;P
sFileName = sName; +<ey Iw
this.nSplitter = nSpiltter; S&P5##.u`
1`_i%R^
wFaWLC|&
} N7xkkAS{
JZQ$*K
^OQ#Nz
public String getSSiteURL() Do|`wpR
{ W$Bx?}x($
return sSiteURL; P( W8XC
} o;JBe"1
I -obfyije
jjm-%W@
public void setSSiteURL(String value) A4?_0:<
{ &~Q ?k
sSiteURL = value; JPk3T.qp
} C6eon4Ut
LV 94i
!m1pL0
public String getSFilePath() dR_hPBn/@
{ w`VmN}pR
return sFilePath; y o[!q|z
} |[TH ~o
sh?Dxodp9
N3H!ptn37
public void setSFilePath(String value) >}/"gx
{ 0nz k?iP
sFilePath = value; 8L 9;VY^Y
} .{-8gAh
UgJ^NF2w
4f"a/(>*
public String getSFileName() ]IJ.}
{ b,G+=&6u
return sFileName; Bd"7F{H
} <S0!$.Kg*<
fK^FD&sF
ki^[~JS>'
public void setSFileName(String value) N2tvP+Z6D
{ Y^S0K'N
sFileName = value; W.n@
} R< xxwjt
^LT9t2
s:cS 9A8
public int getNSplitter() a@,tf'Sr
{ S-yd-MtQp
return nSplitter; YKl!M/
} mXF pGo5 s
<z)MV oa
b)w3 G%Xx
public void setNSplitter(int nCount) k=bv!T_o
{ VV]{R'
nSplitter = nCount; 4'9h^C&
} sS(^7GARa
} =GM!M@~,Ab
HA"dw2|
xYt{=
/* NM~e
**Utility.java YQX>)'
*/ D?5W1m]E,s
package NetFox; o(~JZik
P!YT{}
G';oM;~/|
public class Utility { (DKpJCx
N??<3j+Iu
oRWsi/Zf
public Utility() :@b>,{*4zS
{ a9jY^E'|n
p7H*Ff`
>Q5E0 !]
} ^ad> (W
6o A0a\G'
//线程睡眠 s[s6E`Q
public static void sleep(int nSecond) zLXtj-
{ 7P|(j<JX6'
try{ S8,+6+_7
Thread.sleep(nSecond); `O}. .N]g
} <6L$:vT_
catch(Exception e) N{p2@_fnB
{ <O\z`aA'q
e.printStackTrace (); FT(EH
} [V jd)%
} vlj|[joXw
4?yc/F=kI
//日志 ;-]f4O8
public static void log(String sMsg) ^2^ptQj
{ q9WSQ$:z8
System.err.println(sMsg); 5K6_#g4"
} MB"?^~Sm
Va*Uwy?x/)
,$;CII v
public static void log(int sMsg) .=@M>TZM
{ dqKTF_+VhA
System.err.println(sMsg); +Qc^A
} p Y>yJ)
} Ca1)>1Vz
u5CT7_#)
o!\O)
/* ]B,S<*h
**TestMethod.java b0t];Gc%b
*/ H8-,gV
package NetFox; %] #; ~I%
Yaa M-o
;_Rx|~!!
public class TestMethod { 1@nR.v"$
p6HZ2Q:a
?pF;{
public TestMethod() \ I?;%
{ ///xx/weblogic60b2_win.exe x(=kh%\;
try{ Le3S;SY&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fnmZJJ,Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LiB0]+wzj
SiteFileFetch fileFetch = new SiteFileFetch(bean); m1[QD26
fileFetch.start(); T:!sfhrZ~<
} ,<vrDHR
catch(Exception e){e.printStackTrace ();} "]NQTUb;
G0(c@FBK
ka>RAr J
} KT g$^"\
/p%K[)T(
~hxB Pn."
public static void main(String[] args) q]r!5&Z
{ QKP9*dz
new TestMethod(); k=~?!+p7
} =V,'f
} @`_j't,
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