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)); MVpGWTH@F
} ~p6 V,Q
for(int i=0;i<nEndPos.length-1;i++) u4cnE"
{ &C5_g$Ma.Z
nEndPos = nStartPos[i+1]; IV~>I-rd
} +zqn<<9
nEndPos[nEndPos.length-1] = nFileLength; 7uqzm
} B&M%I:i
} SBu"3ym
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YsC>i`n9
//启动子线程 ,C\i^>=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (!u~CZ;
for(int i=0;i<nStartPos.length;i++) ^cC,.Fdw
{ ^'MT0j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 93>jr<A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *g"Nq+i@
nStartPos,nEndPos,i); 1/B>XkCJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /s&9SYF
fileSplitterFetch.start(); tn\yI!a
} ZoW?nxY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G`D`Af/B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vQG5*pR*w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @Rze| T.
nEndPos = " + nFileLength); ;J( 8 L
// fileSplitterFetch[nPos.length-1].start(); 6xmZXpd!
3lL-)<0A(
F}yW/
//等待子线程结束 ](]i 'fE>
//int count = 0; [-1^-bb
//是否结束while循环 BGZ#wru
boolean breakWhile = false; *->W^1eGM
dA}-]
x M/+L:_<
while(!bStop) Ys9[5@7
{ _IHV7*u{;
write_nPos(); .^33MWu6
Utility.sleep(500); aH(J,XY
breakWhile = true; wYXQlxdy
:wyno#8`-
Vi$~-6n&
for(int i=0;i<nStartPos.length;i++) i$"F{|Z0
{ BN5[,J
if(!fileSplitterFetch.bDownOver) %bn jgy
{ h|9L5
breakWhile = false; Mmj;-u
break; |*eZD-f
} S"QWB`W2
} !RS}NS
if(breakWhile) 5X$jl;6
break; VR8-&N
V*;(kEqj
GT.,
//count++; ;6 D@A
//if(count>4) ea2ayT
// siteStop(); 9Q^r O26+
} K=Z|/Kkh
=!A_^;NQf
%g$o/A$
System.err.println("文件下载结束！"); ^$jb7HMObI
} {%5eMyF#
catch(Exception e){e.printStackTrace ();} ?3`UbN:
} :K,i\
(UD@q>c
k/_ 59@)
//获得文件长度 dh iuI|?@
public long getFileSize() E?f-wQF
{ l}|%5.5-
int nFileLength = -1; DH!~ BB;
try{ OX7M8cmc+
URL url = new URL(siteInfoBean.getSSiteURL()); Yx%Hs5}8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a$OE0zn`
httpConnection.setRequestProperty("User-Agent","NetFox"); X=&ET)8-Y
[=q1T3
9d659iC
int responseCode=httpConnection.getResponseCode(); ^98~U\ar
if(responseCode>=400) Tn e4
{ qOtgve`jX
processErrorCode(responseCode); kd(8I_i@
return -2; //-2 represent access is error `wEb<H
} 20h, ^
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Af2( 5]
String sHeader; e{K 215
-zgI_u9=EB
hBUn \~z
for(int i=1;;i++) nPl?K:(
{ 8C:z"@o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w+|L+h3L7
//Utility.log(in.readLine()); $szqy?i0?
sHeader=httpConnection.getHeaderFieldKey(i); 5r|,CQ7o
if(sHeader!=null) OX!tsARC@
{ 19)i*\+
if(sHeader.equals("Content-Length")) I;|B.j
{ sY Qk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _S1>j7RQo
break; lT?v^\(H
} x~~|.C,
} 8qTys8
else dn+KH+v
break; s};{ZAtE
} ASySiHz
} *Kgks4
catch(IOException e){e.printStackTrace ();} "?xHlYj@+
catch(Exception e){e.printStackTrace ();} D=Gtq6jd
zu{P#~21
,!y$qVg'\f
Utility.log(nFileLength); PiIpnoM
b=NxUd O
xsbE TP?
return nFileLength; WPMSm<[
} )9`qG:b'
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,T$U'&;
//保存下载信息（文件指针位置） +gtbcF@rx
private void write_nPos() OKR "4n:
{ ,/F~Y&1I
try{ WiR(;m<g
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]Ie 0S~
output.writeInt(nStartPos.length); *zvx$yJ?
for(int i=0;i<nStartPos.length;i++) (exa<hh
{ b9HtR-iR;
// output.writeLong(nPos); 6j]0R*B7`Q
output.writeLong(fileSplitterFetch.nStartPos); m8hk:4Ae
output.writeLong(fileSplitterFetch.nEndPos); />pI8 g<
} 6Y?|w3f
output.close(); Fj3a.'
} /]Md~=yNp
catch(IOException e){e.printStackTrace ();} h2]P]@nW;W
catch(Exception e){e.printStackTrace ();} xj;H&swo
} ~IBP|)WA-
qiBVGH
:>f )g
//读取保存的下载信息（文件指针位置） @,7GaK\
private void read_nPos() k)=s>&hl
{ jcf7n`L
try{ joAv{Tc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C1n>M}b
int nCount = input.readInt(); qWPkT$ u
nStartPos = new long[nCount]; A[{yCn`tM
nEndPos = new long[nCount]; CxW>~O:
for(int i=0;i<nStartPos.length;i++) FHg 9OI67
{ 8^1 Te m
nStartPos = input.readLong(); D.u{~
nEndPos = input.readLong(); mL{6L?
} "&?kC2Y|
input.close(); ^A&1^B
} `e&Suyf4B
catch(IOException e){e.printStackTrace ();} G}raA%
catch(Exception e){e.printStackTrace ();} Z0", !6nS
} L^?qOylu
+lcbi
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private void processErrorCode(int nErrorCode) -- 95Jz
{ qt"m
System.err.println("Error Code : " + nErrorCode); .|fHy
} \V~eVf;~
Moza".fiN
j>"@,B g*
//停止文件下载 J<h$ wM
public void siteStop() `l[c_%Bm
{ .?sx&2R2
bStop = true; SZ'R59Ee<
for(int i=0;i<nStartPos.length;i++) flbd0NB
fileSplitterFetch.splitterStop(); ;$wVu|&
Wt-GjxGi
bJTBjS-7
} iz PDd{[
} z$. 88^
//负责部分文件的抓取 Y\8)OBZ
**FileSplitterFetch.java Om2d.7S
*/ ?NsW|w_
package NetFox; WP'!*[z
kxhWq:[c
;dgp+
import java.io.*; 7[XRd9a5(
import java.net.*; +\ .Lp 5
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:':s@gqr
public class FileSplitterFetch extends Thread { 9qzHS~l
WW~sNC\3`(
p}~JgEE
String sURL; //File URL ;[OH(!
long nStartPos; //File Snippet Start Position i<Zc"v;
long nEndPos; //File Snippet End Position VjZ|$k
int nThreadID; //Thread's ID 4!no~ $b
boolean bDownOver = false; //Downing is over Q/0Tj]D
boolean bStop = false; //Stop identical 7;wd(8
FileAccessI fileAccessI = null; //File Access interface `|&O*`
@lrztM
A$0fKko
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Pu$Tk|
{ ;85>xHK
this.sURL = sURL; FWgpnI\X|{
this.nStartPos = nStart; ]Q)OL
this.nEndPos = nEnd; #.)0xfGW)n
nThreadID = id; uz jU2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @`- 4G2IU}
} JP[K;/
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public void run() j'"J%e]
{ JU&c.p /
while(nStartPos < nEndPos && !bStop) <6 Uf.u`
{ \"OG6G_>$
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; )@~
try{ _F|Ek;y%
URL url = new URL(sURL); }N6.Uu5zI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `7V]y-
httpConnection.setRequestProperty("User-Agent","NetFox"); 56kI 5:
String sProperty = "bytes="+nStartPos+"-"; kJT)r6
httpConnection.setRequestProperty("RANGE",sProperty); ;"-&1qHN
Utility.log(sProperty); ,(^*+G.i
ope^~+c~\
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InputStream input = httpConnection.getInputStream(); z5*'{t)
//logResponseHead(httpConnection); l}A93jSL
M&9+6e'-F
60?%<oJ oH
byte[] b = new byte[1024]; tW}'g:s
int nRead; \xw5JGm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q(W3i^778
{ FP4P|kl/9'
nStartPos += fileAccessI.write(b,0,nRead); 5D//*}b,
//if(nThreadID == 1) &Hs!:43E-<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3{sVVq5Y
} T'Dv.h
[2M'PT3
T%*D~=fQ'
Utility.log("Thread " + nThreadID + " is over!"); ]2qo+yB
bDownOver = true; uiR8,H9*M
//nPos = fileAccessI.write (b,0,nRead); DT&@^$?
} 07{)?1cod4
catch(Exception e){e.printStackTrace ();} t&e{_|i#+
} }a(dyr`S
} 0*{%=M
m GYoM
k!'a,R:
//打印回应的头信息 ,/|T-Ka
public void logResponseHead(HttpURLConnection con) m#\dSl}
{ {V CWn95Z
for(int i=1;;i++) )irEM
{ 'YSHi\z ](
String header=con.getHeaderFieldKey(i); z9Rp`z&`E
if(header!=null) 3eQ&F~S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `*1p0~cu
Utility.log(header+" : "+con.getHeaderField(header)); p>8D;#HmL
else 0{-q#/
break; NyNXP_8
} ' %o#q6O
} WX3-\Y5E
"87:?v[[1
=fFP5e ['
public void splitterStop() sdw(R#GE
{ =]0&i]z[.
bStop = true; v0.#Sl-
} > /caXvS
)bscBj@
T{[=oH+
} X$W~mQma6
<frutU16\
; kI134i=
/* ge8ZsaiU
**FileAccess.java 3L}A3de'
*//文件访问(定位，写) H6/$d
package NetFox; \z(gqkc 6
import java.io.*; q^<?]8
II{&{S'HU
p H2Sbs:Tk
public class FileAccessI implements Serializable{ v):Or'$~M
ji0@P'^;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t\7[f >
RandomAccessFile oSavedFile; z!9-:
long nPos; E+;7>ja
</*6wpN
>tW#/\x{
public FileAccessI() throws IOException sLxc(d'A
{ o|["SYIf
this("",0); A^<jy=F&
} |aq"#Ml)
JDT`C2-Q
P@c5pc#|
public FileAccessI(String sName,long nPos) throws IOException aAUvlb
{ r\^b(rNe
oSavedFile = new RandomAccessFile(sName,"rw"); m!HJj>GEo
this.nPos = nPos; RPRBmb940
oSavedFile.seek(nPos); Z/+#pWBI!
} 6(ol1 (U
$1`2kM5
cSV aI
public synchronized int write(byte[] b,int nStart,int nLen) DN:EB@
{ \ }G>8^
int n = -1; k;FUs[
try{ 3)ywX&4"L
oSavedFile.write(b,nStart,nLen); ^k9I(f^c-_
n = nLen; {3aua:q
} -ZLJeY L
catch(IOException e) #KZBsa@p
{ ;NITc
e.printStackTrace (); f%}xO+.s
} s?nR4
(<C3Vts))
U # qK.
return n; 9djk[ttA)
} }*]-jWt1J\
1iF1GkLEq
pYf-S?Y/V
} =D"#U#>;7&
{R`[kt
NTs aW}g
/* Z(CkZll
**SiteInfoBean.java "=MeM)K
*/ e$rZ5X
package NetFox; b d!Y\OD
t"oeQ*d%
I-l_TpM)
public class SiteInfoBean { &{t,'[ u
M9%$lCl
5:_}zu|!u
private String sSiteURL; //Site's URL j1T#yt J
private String sFilePath; //Saved File's Path 1bwOmhkS
private String sFileName; //Saved File's Name ^^ixa1H<
private int nSplitter; //Count of Splited Downloading File ' S/gmn
fe_5LC"
3%b6{ie/=
public SiteInfoBean() GnJt0{
{//nSplitter的缺省值为5 G]&qx`TBK
//default value of nSplitter is 5 nAlQ7'
this("","","",5); +mT_QsLEv
} |+D!= :x
a9Zq{Ysj
FfT`;j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .8JTe0
{ 88$8d>-
sSiteURL= sURL; 5\VWCI
sFilePath = sPath; c@L< Z`u
sFileName = sName; U|R_OLWAg
this.nSplitter = nSpiltter; H0vfUF53l
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l+0oS'`V*L
} BnF^u5kv%
8zW2zkv2|#
Nu)NqFG,
public String getSSiteURL() =Nr-iae#
{ g*+>H1}
return sSiteURL; a/xn'"eli
} 19%imf
\1M4Dl5!
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public void setSSiteURL(String value) SNk=b6`9
{ ysnx3(+|
sSiteURL = value; ('+d.F[109
} F#5~M<`.o
K_}K@'
>Y@H4LF;1x
public String getSFilePath() M x"\5i
{ z},# ~L6$q
return sFilePath; jq0O22 -R
} W: z;|FF
Q\sK"~@3
]JQULE)
public void setSFilePath(String value) $U-0)4yf
{ vo{--+{ky!
sFilePath = value; %JTpI`
} 4 s9LB
t\O16O7S
!^G\9"4A
public String getSFileName() lNO;O}8
{ C~exi[3
return sFileName; rEz^
} :NTO03F7v
`N8O"UcoBo
A?OQE9'
public void setSFileName(String value) &_8947
{ }"%N4(Kd
sFileName = value; M&M6;Ph
} _ jlRlt
|CbikE}kL
@BMx!r5kn
public int getNSplitter() goWuw}?
{ b" [|:F>P
return nSplitter; #fM`}Ij.A
} P16~Qj
VuZr:-K/
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public void setNSplitter(int nCount) Z0r'S]fe
{ yEy6]f+>+
nSplitter = nCount; \o3gKoL%
} M X]n&
} KwVbbC3
t"I77aZ$A
8zq=N#x
/* n~Lt\K:
**Utility.java <IW$m!{VG
*/ @IZnFHN
package NetFox; ~pky@O#b
uCB=u[]y4
;722\y(Y
public class Utility { z\4.Gm-
`uTmw^pZX
1G`Pmh@
public Utility() <wHP2|<l*
{ }Ou}+^Bc
+LJ73 !
u)Whr@m
} 8H`[*|{'
]hV*r@d
//线程睡眠 &BSn?
public static void sleep(int nSecond) :b!s2n!u
{ X"*5+* z]
try{ AbOf6%Env
Thread.sleep(nSecond); RPbZ(.
} +aAc9'k
catch(Exception e) 2st3
{ #Bw0,\
e.printStackTrace (); IdN41
} U #0Cx-E
} 0PCGDLk8
\z)%$#I
//日志 B`sAk %
public static void log(String sMsg) ?gXp*>Kg[
{ a,o*=r
System.err.println(sMsg); pTuS*MYz
} QTnP'5y
ksm~<;td
e+=K d+:k
public static void log(int sMsg) iN.n8MN=I
{ l}P=/#</T
System.err.println(sMsg); tT._VK]o&R
} Ew$C ;&9
} NX&_p!_V
dQG=G%W
\ 6MCxh6
/* bhs _9ivw
**TestMethod.java .A|@?p[
*/ :Iz8aQ
package NetFox; WfRXP^a
3iU=c&P
DW3G
public class TestMethod { og>uj>H&
4I(Xy]wm
!TcJ)0
public TestMethod() bN=P*hdf
{ ///xx/weblogic60b2_win.exe [PbOfxxgA
try{ &6k3*dq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7PF%76TO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,tRj4mx
SiteFileFetch fileFetch = new SiteFileFetch(bean); fd9k?,zM
fileFetch.start(); L\iFNT}g`
} VG~Vs@c(
catch(Exception e){e.printStackTrace ();} KG{St{uJ
,iwp,=h=
=WJNWt>
} `QY)!$mUIF
;GD]dW#
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public static void main(String[] args) 4`=mu}Y2
{ |+"(L#wk
new TestMethod(); ]{>,rK[So
} U`s{Jm
} 3=;<$+I6
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