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)); SD)5?{6<
} 7qCJ]%)b6
for(int i=0;i<nEndPos.length-1;i++) 6 ,7/8
{ aeN}hG
nEndPos = nStartPos[i+1]; {JCSR2BB
} #j(q/ T{x
nEndPos[nEndPos.length-1] = nFileLength; W;xW: -
} K0d-MC
} RTdD]pE8Q
Z!q2F%02FO
.6lY*LI
//启动子线程 ;t.SiA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s!8J.hD'I
for(int i=0;i<nStartPos.length;i++) T4%i`<i
{ M="WUe_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D#vn {^c8O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _ Yb Eo+
nStartPos,nEndPos,i); sR7{i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w>H%[\Qs
fileSplitterFetch.start(); N7RG5?
} 8GF[)z&|P:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [[Jv)?jm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZuF4N=;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _qO;{%r
nEndPos = " + nFileLength); wiK@o$S-
// fileSplitterFetch[nPos.length-1].start(); |!jYv'%
1 $KLMW
Z9;nC zHm
//等待子线程结束 e)ZyTuj
//int count = 0; #Tgz,e9
//是否结束while循环 Egjk^:@
boolean breakWhile = false; [9YlLL@
{WM&
e4>L@7
while(!bStop) 4 _c:Vl
{ = C$@DNEc
write_nPos(); qH{8n`
Utility.sleep(500); ulz\x2[Pf
breakWhile = true; E,ZB;
R%]9y]HQ
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for(int i=0;i<nStartPos.length;i++) N%n1>!X)!
{ 7(+OsE
if(!fileSplitterFetch.bDownOver) M'>D[5;N~
{ lD;,I^Lt6
breakWhile = false; Up!ZCZ$RC
break; :#Ex3H7
} dEAAm=K,<
} u75)>^:I
if(breakWhile) %1 VNP(E
break; ZB_16&2Ow
]`/R("l[
^ T:qT*v
//count++; 2=!3[> B
//if(count>4) c=jI.=mi3
// siteStop(); YjIED,eRv
} _/z)&0DO
?V\9,BTb)
xP5mL3j
System.err.println("文件下载结束！"); xj00eL
} \{+nXn
catch(Exception e){e.printStackTrace ();} B;D:9K
} .olPm3MC
#1qVFU
~D`oP/6
//获得文件长度 MRVz:g\mi
public long getFileSize() u{{xnyl?
{ HA3SQ
int nFileLength = -1; x4HMT/@AG2
try{ Edn$0D68u_
URL url = new URL(siteInfoBean.getSSiteURL()); GHgEbiY:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !ovZ>,1
httpConnection.setRequestProperty("User-Agent","NetFox"); Cf1wM:K|8
sKB-7
s>M~g,xTU
int responseCode=httpConnection.getResponseCode(); 7L~ zI>2
if(responseCode>=400) jO3u]5}.6
{ `6S=KRv
processErrorCode(responseCode); A*26'
return -2; //-2 represent access is error j2{,1hj
} UN .[,%<s
VjB`~
^* /v,+01f
String sHeader; LN3dp?;_{
7^t(RNq
'*LN)E>d
for(int i=1;;i++) :Z]+Z_9p
{ Hb AMoow!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %_@5_S
//Utility.log(in.readLine()); HfeflGme*
sHeader=httpConnection.getHeaderFieldKey(i); 6`5 @E\"E
if(sHeader!=null) KutgW#+40
{ Q"K>ML>0
if(sHeader.equals("Content-Length")) Xx<&6 4W
{ =*>4Gh i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Nec(^|[
break; ~ GT\RAj[
} % x*Ec[l
} d @kLLDP
else qL;T&h
break; (7jB_ p%
} ,ZP3F+XKb
} U#]eN[
catch(IOException e){e.printStackTrace ();} )!*M 71
catch(Exception e){e.printStackTrace ();} zf;[nz
dV=5_wXZ$
z9kX`M+
Utility.log(nFileLength); UV8r&O
c+i`Zd.m<
yjFQk,A
return nFileLength; >=W#z
} ,JBw$C
A%w]~ chC9
'%RK KA
//保存下载信息（文件指针位置） ;@Hi*d[
private void write_nPos() <C96]}/ ?
{ '>mb@m
try{ -r'seb5
output = new DataOutputStream(new FileOutputStream(tmpFile)); |{LaZXU&
output.writeInt(nStartPos.length); WAmoKZw2
for(int i=0;i<nStartPos.length;i++) -hR\Y2?
{ &b6@_C9
// output.writeLong(nPos); -GWzMBS S
output.writeLong(fileSplitterFetch.nStartPos); :E&T}RN
output.writeLong(fileSplitterFetch.nEndPos); Nu2]~W&
} tP(bRQ>
output.close(); v*fc5"3eO
} SF7b1jr
catch(IOException e){e.printStackTrace ();} 4kF .
catch(Exception e){e.printStackTrace ();} t\bxd`,
} @>nk^l
z==}~|5
8lGgp&ey
//读取保存的下载信息（文件指针位置） &trh\\I"
private void read_nPos() :h^UC~[h 3
{ O8N0]Mz
try{ &r5%WRzpYT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YJvT p~
int nCount = input.readInt(); `"":
nStartPos = new long[nCount]; <\>ak7m
nEndPos = new long[nCount]; B:#0B[
for(int i=0;i<nStartPos.length;i++) wvaIgy%z
{ {#M{~
nStartPos = input.readLong(); uWtS83i
nEndPos = input.readLong(); 2LH;d`H[0
} |=}~>!!
input.close(); IeI%X\G
} U105u.#7
catch(IOException e){e.printStackTrace ();} $hp?5KM
catch(Exception e){e.printStackTrace ();} ;~$ $WU
} RW[<e
$<e .]`R
;p!hd}C
private void processErrorCode(int nErrorCode) )mVYqlU"
{ (wF$"c3'{
System.err.println("Error Code : " + nErrorCode); `3P62M<
} sZBO_](S
_H<OfAO
6Q.whV%y
//停止文件下载 Ki;5 =)
public void siteStop() QO1Gq9
{ /M `y LI
bStop = true; ~0GX~{;r
for(int i=0;i<nStartPos.length;i++) VZbIU[5
fileSplitterFetch.splitterStop(); ;OqLNfU3y
#f;1f8yrN
zn$Ld,
} <%uZwk>#
} TiEJyd`P
//负责部分文件的抓取 '6J$X-
**FileSplitterFetch.java u`,R0=<4
*/ bO3KaOC8N
package NetFox; 48rYs}
>8t[EsW/
Yx c >+mx
import java.io.*; @|A&\a-"J
import java.net.*; sswAI|6ou
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public class FileSplitterFetch extends Thread { 7B"aFnK;[J
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o;C)!
String sURL; //File URL d0E5;3tQ
long nStartPos; //File Snippet Start Position :u93yH6~8
long nEndPos; //File Snippet End Position q`zR6
int nThreadID; //Thread's ID [c )\?MWW
boolean bDownOver = false; //Downing is over -ouL4
boolean bStop = false; //Stop identical sJ()ItU5i
FileAccessI fileAccessI = null; //File Access interface scwlW b<N
?KW?] o
I65GUX#DV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :\We =oX
{ kIo?<=F8T
this.sURL = sURL; $R36`wk
this.nStartPos = nStart; KO$8lMm$
this.nEndPos = nEnd; 5|z[%x~f
nThreadID = id; f2f$aZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]^%3Y
} K2v)"|T)
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public void run() CcETS}Q0C
{ +O6@)?pI
while(nStartPos < nEndPos && !bStop) y+h=x4t
{ Gl9a5b
B`Pi\1H6%
{+}Lc$O#C
try{ $%t
URL url = new URL(sURL); qILr+zH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mAKi%)
httpConnection.setRequestProperty("User-Agent","NetFox"); EB,>k1IJ
String sProperty = "bytes="+nStartPos+"-"; rR;Om1 -,
httpConnection.setRequestProperty("RANGE",sProperty); Gu=bPQOj
Utility.log(sProperty); vS<e/e+
#k, kpL<a
><^@1z.J
InputStream input = httpConnection.getInputStream(); ~.tu#Y?
//logResponseHead(httpConnection); Sj+#yct-
PX'%)5:q;i
:#;?dMkTY
byte[] b = new byte[1024]; `dhK$jYD
int nRead; fRmc_tx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .=S{
{ _>l,%n
nStartPos += fileAccessI.write(b,0,nRead); I&0yUhn
//if(nThreadID == 1) z/=v@@tj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NeP1 #
} ( d.i np(
hJ :+*46
f5v|}gMAX
Utility.log("Thread " + nThreadID + " is over!"); %iNDRLR%I
bDownOver = true; IA'AA|v
//nPos = fileAccessI.write (b,0,nRead); To+{9"$,
} Ws(>} qjy
catch(Exception e){e.printStackTrace ();} ?a}~yz#B(
} ]]4E)j8
} + h&V;
f#jAjzmYL
=O<BMq{d
//打印回应的头信息 rO~D{)Nu
public void logResponseHead(HttpURLConnection con) VTdZ&%@
{ mB\|<2
for(int i=1;;i++) 0=iJT4IEJ
{ o2L/8q.
String header=con.getHeaderFieldKey(i); \l~h#1|%;s
if(header!=null) lbY>R@5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n3w2&
Utility.log(header+" : "+con.getHeaderField(header)); i F Ab"VA
else T+fU+GLD
break; E^!%m8--
} `i-&Z`
} i || /=ai
K67x.PZ
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public void splitterStop() = ~yh[@R)
{ 2r[,w]
bStop = true; V2*b f`/V
} r|(Lb'k
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+W}f0@#)<
} 8PQ& 7o
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$]9d((u4
/* 0y(d|;':
**FileAccess.java C1_NGOvT
*//文件访问(定位，写) CA3.fu3(p
package NetFox; c{[d@jtO
import java.io.*; 6Z3v]X
p|Ln;aYc
X'5te0v`3
public class FileAccessI implements Serializable{ e2;">tp6?
7YsFe6D"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c;Li~FLR
RandomAccessFile oSavedFile; I|:*Dy,~
long nPos; OIN]u{S
4CDmq[AVS[
k;%}%"EVZ
public FileAccessI() throws IOException 2$jY_{B+x
{ nX
this("",0); P~~RK&+i
} Axr'zc
JO _a+Yl
bBZvL
public FileAccessI(String sName,long nPos) throws IOException @sVBG']p
{ XOxm<3gXn
oSavedFile = new RandomAccessFile(sName,"rw"); 3M^ /
this.nPos = nPos; C?zC|0
oSavedFile.seek(nPos); @x)z" )>
} Q (`IiV
'0[l'Dt'
__zsrIUJ
public synchronized int write(byte[] b,int nStart,int nLen) >~6 ;9{@
{ L,R9jMx?_
int n = -1; \PL92HV
try{ %bddR;c
oSavedFile.write(b,nStart,nLen); rt"\\sOlMB
n = nLen; Y#uf 2>J
} hj-M #a
catch(IOException e) Z";o{@p
{ ;v.l<AOE
e.printStackTrace (); }UX>O
} Xc'yz 2B
<n0-zCf
nPKf~|\1{
return n; R_/T bz
} HgbJsv$
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$+$+;1[
} $.v5G>-)3
GAQVeL1
ZQ@^(64
/* ([s2F%S`@
**SiteInfoBean.java HAP9XC(F]
*/ ,~c:P>v=
package NetFox; KWM.b"WnXr
F7a\Luae
QRx'BY$5
public class SiteInfoBean { KrG$W/<tg
$YFn$.70\
%$S.4#G2
private String sSiteURL; //Site's URL Zb3E-'G+
private String sFilePath; //Saved File's Path Ktg6*L/
private String sFileName; //Saved File's Name 3xbA]u;gp
private int nSplitter; //Count of Splited Downloading File u6|P)8?`
"c=\?
lZ'NLbK
public SiteInfoBean() izOtt^#DZt
{//nSplitter的缺省值为5 J/WPffqD
//default value of nSplitter is 5 yG{'hx6H
this("","","",5); SkVW8n*s
} -&%#R_RV
XP~4jOL]
{-tCLkE 3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =[3I#s?V
{ rC$ckug
sSiteURL= sURL; ps^Z)x`GV
sFilePath = sPath; n*hHqZl
sFileName = sName; (hs[B4nV
this.nSplitter = nSpiltter; cC b'z1
u0Irf"Ab
nu|;(ly
} mQ:lj$Gf
?kISAA4x
Sycs u_je
public String getSSiteURL() 9!}&&]Q`
{ `gSqwN<x%
return sSiteURL; ;WWUxrWif
} +)dQd T0Fq
+'x|VPY.PG
5W(G~m?jC6
public void setSSiteURL(String value) mtvfG
{ t,)`Zu$
sSiteURL = value; now\-XrS
} uwU;glT
+Gg6h=u
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public String getSFilePath() ~L<q9B( @
{ [f!sBJ!
return sFilePath; Mnn\y Tblp
} 6p=AzojoB
_ )b:F=4j
@rB!47!
public void setSFilePath(String value) :}i #ODJ
{ 0hp*(, L
sFilePath = value; `%SFu
} j,?>Q4G
}`FC'!(
FZ)_WaqGf
public String getSFileName() ""|vhgP
{ _l<e>zj
return sFileName; HTA@en[5
} p(g0+.?`~
S:"R/EE(
Lnc _)RF
public void setSFileName(String value) :OT~xU==H
{ 5xtIez]x?
sFileName = value; 2K0HN
} aY&He~
A%qlB[!:
y9kydu#q
public int getNSplitter() $k5mI1~
{ V<A_c^unO
return nSplitter; J$JXY@mBSC
} f?}~$agc
B! $a Y
+n_`*@SE
public void setNSplitter(int nCount) U{6i5;F#H
{ w7GF,a
nSplitter = nCount; %%5K%z,R#
} @62QDlt;
} x=7hOI5u
p^S]O\;M7
Z\Qa6f!
/* ZU\TA|
**Utility.java "N\>v#>C
*/ t 1gH9
package NetFox; CvDy;'{y1
vl+vzAd
C QO gR GW
public class Utility { T"ors]eI
I`"B<=zi
94Wf ]
public Utility() 1xAZ0X#
{ CDOqdBQ
5[NF
u xif-5
} LU "e9
a:nMW'!
//线程睡眠 MHZ!noAr
public static void sleep(int nSecond) ~&)
{ Id-?her>B
try{ R?bF b|5t
Thread.sleep(nSecond); m<]b]FQ
} _c|aRRW
catch(Exception e) eTi r-7
{ +o&&5&HR
e.printStackTrace (); Z[+H$=$%
} ;533;(d*o
} TK"!z(p
NY]`1yy
//日志 O}VI8OB(&
public static void log(String sMsg) E*rnk4Y
{ X2ShxD|
System.err.println(sMsg); 9AJMm1_
} hN% h.;s
"n'LF?/H'
z>_jC+
public static void log(int sMsg) -.#He
{ M+Rxt.~6
System.err.println(sMsg); \gd.Bl
} {UX[SAQ
} X8U._/'N
G4Y]fzC
Q{9#Am^6w
/* e[D'0L
**TestMethod.java Yjo$^q
*/ +bnz%/v
package NetFox; v&CKtk!3{
!Pmv
Rb_HD
public class TestMethod { /mST<{(_G\
v&:R{
T""y)%
public TestMethod() GdN'G
{ ///xx/weblogic60b2_win.exe y@!kp*0
try{ n1Ag o3NM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r{m"E^K,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *.ffyBI*~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1zE_ SNx
fileFetch.start(); ,O=@I
} 'WH@Zk/l
catch(Exception e){e.printStackTrace ();} E|2klA^+*
G $u:1&
'ad|@Bh
} wzAp`Zs2Dm
ldJeja~Xl
IQK__)
public static void main(String[] args) 6"Tr$E
{ %v++AcE
new TestMethod(); |L{<=NNs:D
} dy u brIG
} ZgO7W]Z4
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