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{LDtn%@h6
} bP Er+?fu
for(int i=0;i<nEndPos.length-1;i++) )~O{jd
{ JXGIVH?Rpu
nEndPos = nStartPos[i+1]; Rmn|"ZK
} YurK@Tq7
nEndPos[nEndPos.length-1] = nFileLength; 3>0/WbA:7E
} /,/T{V[
} 1B6Go
<hdR:k@#
\"_;rJ{!aE
//启动子线程 *2 4P T7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xh@H@Q\
for(int i=0;i<nStartPos.length;i++) doP4N6
{ sG0cN;I]t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /zuU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;#3!ZB:}
nStartPos,nEndPos,i); Q2^}NQO=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vjZX8KAiZ
fileSplitterFetch.start(); ~{Tus.jk
} T {(6*^g<B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 20zIO.&o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "KW\:uc /
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @6 gA4h
nEndPos = " + nFileLength); 0$}+tq+
// fileSplitterFetch[nPos.length-1].start(); A7+eWg{
[ #A!B#`
yXppu[=
//等待子线程结束 M)I&^mm39
//int count = 0; 5U3="L
//是否结束while循环 :5U(}\dL{
boolean breakWhile = false; ',kYZay
4zpprh+`K
/r[0Dw
while(!bStop) ub+>i
{ 0RYh4'=F
write_nPos(); SG8|xoL
Utility.sleep(500); HP. j.
breakWhile = true; 6;I&{9
UG&/0{j5XV
G}BO!Z6
for(int i=0;i<nStartPos.length;i++) Tp)-L0kD_k
{ YmB z$
if(!fileSplitterFetch.bDownOver) FFR_1Vf
{ K$#(\-M
breakWhile = false; -g;iMqh#
break; -7'>Rw
} {{SQL)yJ
} G0CmY43
if(breakWhile) _s|C0Pt
break; ~hE"B) e
tE3!;
-AD3Pd|Y[
//count++; ;8|uY%ab
//if(count>4) =6ZZ/+6b
// siteStop(); Ct|iZLh`j
} Eae]s8ek9
N=zrY`Vd
3)atqM)i
System.err.println("文件下载结束！"); %:N5k+}
} ~-A5h(
catch(Exception e){e.printStackTrace ();} yGZb
} $khWu>b
^Ml)g=Fq
'r(}7>~fC
//获得文件长度 zK k;&y|{
public long getFileSize() ?bmP<(N5/
{ T.`EDluG
int nFileLength = -1; .N5}JUj
try{ 5``/exG>
URL url = new URL(siteInfoBean.getSSiteURL()); ,Tvk&<!0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dx4?6
httpConnection.setRequestProperty("User-Agent","NetFox"); *-3K],^a
}/SbmW8(1
a7%5Qg9B;
int responseCode=httpConnection.getResponseCode(); nP0|nPWz#
if(responseCode>=400) O<Ht-TN&
{ ou6yi; l%
processErrorCode(responseCode); @4sv(HyDY
return -2; //-2 represent access is error (05/}PhB`
} 2%. A{!
pu0IhDMn
3-lJ]7OT
String sHeader; }_@*,
9=ns.r
U;`N:~|p#
for(int i=1;;i++) r_@;eh
{ M//q7SHh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -3_-n*k!
//Utility.log(in.readLine()); Al5E
sHeader=httpConnection.getHeaderFieldKey(i); rs]%`"&=
if(sHeader!=null) g&`e2|[7
{ #[qmhU{s
if(sHeader.equals("Content-Length")) =n cu#T]
{ 8l~]}2LAs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ltwX-
break; aiF7\^aw$
} brl(7_2
} r0+lH:G*q
else g`d5OHvOo
break; ; "ux{ .
} 0x4Xs
} K``MS
catch(IOException e){e.printStackTrace ();} #OqQD6
catch(Exception e){e.printStackTrace ();} plh.-"
I ^?TabL
Q0#oR[(
Utility.log(nFileLength); Rf^$?D&^
|j^^*z@
~-.}]N+([
return nFileLength; $.a<b^.Xi
} o:.={)rX
5@%$M$E
MT[V1I{LV
//保存下载信息（文件指针位置） IGV@tI
private void write_nPos() Nv,1F
{ -=H*(M
try{ yS[:C 2v
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0BMKwZg
output.writeInt(nStartPos.length); sX.L
for(int i=0;i<nStartPos.length;i++) EeIV6ug
{ )D{L<.i_
// output.writeLong(nPos); b^~ keQ
output.writeLong(fileSplitterFetch.nStartPos); A5S9F8Q/]
output.writeLong(fileSplitterFetch.nEndPos); 1p[C5j3
} <4ccTl
output.close(); ` .|JTm[
} [a:yKJ[
catch(IOException e){e.printStackTrace ();} ,|D_? D)U
catch(Exception e){e.printStackTrace ();} (#k>cA(}
} )e d5~ok
4/;hA z
jVC`38|
//读取保存的下载信息（文件指针位置） 5=WzKM
private void read_nPos() !_ZknZTT
{ 4zkn~oy
try{ %PRG;kR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (OwAhjHE
int nCount = input.readInt(); ea kj>7\s
nStartPos = new long[nCount]; )r3}9J
nEndPos = new long[nCount]; :hJHjh
for(int i=0;i<nStartPos.length;i++) n+QUT
{ /{>$E>N;
nStartPos = input.readLong(); cKJf0S:cx-
nEndPos = input.readLong(); cXU8}>qY7
} w#vSZbh
input.close(); Zyt,D|eWj
} "(zvI>A
catch(IOException e){e.printStackTrace ();} #tg,%*.s
catch(Exception e){e.printStackTrace ();} >Akrbmh5
} 9>yLSM,!rS
M<s16
4[m})X2(
private void processErrorCode(int nErrorCode) xP#vAR
{ F0:|uC4
System.err.println("Error Code : " + nErrorCode); $\M<gW6
} J@sH(S
6_]-&&Nr
4Vl_vTz{i
//停止文件下载 eG&\b-%
public void siteStop() d3-F?i 5d
{ *`2.WF@E)
bStop = true; =lT~
for(int i=0;i<nStartPos.length;i++) I,TJV)B
fileSplitterFetch.splitterStop(); ,cZhkXd
l/1u>'
GKT2x '(e
} Fa<>2KkOr
} W!vN(1:(
//负责部分文件的抓取 G&=4@pLY5
**FileSplitterFetch.java ,)/gy)~#
*/ (3cJ8o>&
package NetFox; hgIqr^N9
H'KCIqo
P 4Vi~zMX
import java.io.*; BIGln`;,f
import java.net.*; wJyrF
tpu2e*n-|
URU,&gy=
public class FileSplitterFetch extends Thread { 0U|t@&q
Hdvtgss!
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String sURL; //File URL G>Fk )
long nStartPos; //File Snippet Start Position \WS2g"(
long nEndPos; //File Snippet End Position KaVNRS
int nThreadID; //Thread's ID s?Lx\?T
boolean bDownOver = false; //Downing is over Z|3fhaT
boolean bStop = false; //Stop identical .#^ta9^t7
FileAccessI fileAccessI = null; //File Access interface ?tzJ7PJ~B
be?>C 5
],`xd_=]=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7egE."
{ aa|u*afWQ
this.sURL = sURL; UWU(6J|Fk
this.nStartPos = nStart; ] V|hDU=t
this.nEndPos = nEnd; xgDd5`W
nThreadID = id; 5OEo(&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a8 X}r.
} #IJm*_J<
44Dytpvg
AWaptw_p*
public void run() /{1sU}k-
{ yyPQ^{zD
while(nStartPos < nEndPos && !bStop) "PgVvm#w'
{ MB7UI8
M3XG s|gw
6HroKu
try{ 9S'u1%
URL url = new URL(sURL); E_q/*}]pE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L hp
httpConnection.setRequestProperty("User-Agent","NetFox"); x,wXR=H
String sProperty = "bytes="+nStartPos+"-"; V52>K$j
httpConnection.setRequestProperty("RANGE",sProperty); @JW HG1qJ
Utility.log(sProperty); CzMCd ~*7R
0gRj3al(
8Z&M}Llk
InputStream input = httpConnection.getInputStream(); ,LE15},
//logResponseHead(httpConnection); vCvjb\S
ML_$/
1G}f83yR
byte[] b = new byte[1024]; 4^r4O#
int nRead; iGq%|o>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FOPfob[
{ F u>
nStartPos += fileAccessI.write(b,0,nRead); vYFtw L`
//if(nThreadID == 1) @%lkRU)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $>JfLSyC
} 5)5$h]Nz>
uzoI*aqk-s
-L-#-dK'
Utility.log("Thread " + nThreadID + " is over!"); 2[Ofa(mkkp
bDownOver = true; sKy3('5;
//nPos = fileAccessI.write (b,0,nRead); <OH{7>V
} WCTmf8f
catch(Exception e){e.printStackTrace ();} e{Q;,jsh
} ai7R@~O:_k
} "D\>oFu
BGd# \2
Bd'X~Vj<
//打印回应的头信息 ?"F9~vx&G
public void logResponseHead(HttpURLConnection con) ol0i^d*9F
{ (k^%j
for(int i=1;;i++) 7vo8lnQ{
{ Ln'y 3~@
String header=con.getHeaderFieldKey(i); ,.kJF4s&
if(header!=null) U[0x\~[$K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HVJqDF
Utility.log(header+" : "+con.getHeaderField(header)); a8WWFAC[
else }/w]+f*
break; m?<^b_a}
} z@g%9|U
} &k@\k<2Ia
XE>w&
LR "=(
public void splitterStop() XF&_**0n
{ `@q\R-`
bStop = true; ^B_SAZ&%%
} kYhV1I
)[S#:PP
r>e1IG
} $7QGi|W*k
l k sNy
lfAiW;giJ
/* TU6(Q,Yi|
**FileAccess.java mtg=v@~
*//文件访问(定位，写) xfF;u9$;
package NetFox; tj?%{L
import java.io.*; r|63T%q!
HA J[Y3d<
kwXUjnp
public class FileAccessI implements Serializable{ `h|Y0x
cP",szcY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Dm@h'*
RandomAccessFile oSavedFile; n^q%_60H
long nPos; qyBC1an5,
'fs tfk
PNz]L
public FileAccessI() throws IOException bUsX~R-
{ *rgF[ :
this("",0); y6dQ4Whv&
} rB|1<jR
vX7U|zy
?n]adS{
public FileAccessI(String sName,long nPos) throws IOException k:&vW21E
{ yq?\.~ax
oSavedFile = new RandomAccessFile(sName,"rw"); }S$OE))u
this.nPos = nPos; 5hHLC7tT9
oSavedFile.seek(nPos); 3ey.r%n
} cL<,]%SkE
X }`o9]y
xnC:?d
public synchronized int write(byte[] b,int nStart,int nLen) @Di!~e6
{ AdpJ4}|0
int n = -1; gg/ts]$
try{ <PFF\NE9
oSavedFile.write(b,nStart,nLen); q;lR|NOh
n = nLen; (rc7Cp3
} W}y)vrL
catch(IOException e) c1q;
{ Gshy$'_e
e.printStackTrace (); EJP]E)
} '6kD6o_p1
E/hT/BOPK
i)]f0F
return n; oiIl\#C
} [dR#!"6t
id588Y78
>=d 5Scix
} !PA><F
'`YZJ
]WzeJ"r {3
/* ^9`|QF
**SiteInfoBean.java joDqv,iW8
*/ `M*jrkM]x
package NetFox; op@=0d??
g${JdxR:
bSz@@s.
public class SiteInfoBean { V%{WH}
ek.@ 0c
rq^%)tR
private String sSiteURL; //Site's URL =k*XGbU
private String sFilePath; //Saved File's Path kdWUz(
private String sFileName; //Saved File's Name <$@I*xk[
private int nSplitter; //Count of Splited Downloading File ,N_/J4Us
wMw}3qX$j
J0 dY%pH#
public SiteInfoBean() Vo6+|ztk|
{//nSplitter的缺省值为5 vsyg u
//default value of nSplitter is 5 n=PfV3B
this("","","",5); u(fZ^
} gkX7,J-0
P^# 4m
Y]*&\Ex"\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j/_&]6!
{ D^2lb"3
sSiteURL= sURL; @}19:A<'
sFilePath = sPath; \>>P%EU,
sFileName = sName; -$kIVh
this.nSplitter = nSpiltter; b\KbF/T
FrUqfTi+W
/\_n5XI1
} +I-BqA9
kh{3s:RQfC
1hlU 6=Y
public String getSSiteURL() MRw4?HqB
{ ?:M4GY"gV
return sSiteURL; [KFCc_:
} q2r$j\L%
o ^ \+Ua
.P`QCH;Ih
public void setSSiteURL(String value) $}r.fji,c
{ Zxd*%v;
sSiteURL = value; "OA{[)fw"
} =E>P,"D
zfE8=d8U
>MKj~Ud
public String getSFilePath() zH Z;Y^{+
{ t1U+7nM
return sFilePath; K9.Gjw
} '.;{"G.@'
_~MX~M3MB
wPm
public void setSFilePath(String value) |`Noj+T47I
{ (hdu+^Qj=
sFilePath = value; SASLeGaV
} jI0gf&v8
c|`$ h
}IZw6KiN
public String getSFileName() _{;_wwz
{ 9PACXW0
return sFileName; hdi0YL
} lZ7 $DGe
x{8h3.ZQ,
0MroHFh9`
public void setSFileName(String value) @&EIH,c
{ ,Pcg+^A
sFileName = value; [FrLxU
} czU"
V2`Ud[
uDXV@;6<
public int getNSplitter() Z]R#F0"U
{ qB,0(I1-!
return nSplitter; zRD-[Z/-
} cV0CI&
,c^nW
"OK[uug
public void setNSplitter(int nCount) ypG*41
{ 1AN$s
nSplitter = nCount; ppNMXbXR
} NN=^4Xpc:
} 23i2yT
G`kz 0Vk
U|Gy9"
/* [:#K_EI5%
**Utility.java T]Ai{@i
*/ _K!.TM+9
package NetFox; |idw?qCn
2nC,1%kxhq
rIJPgF
public class Utility { UWqD)6
mICEJ\`x
ni%)a
public Utility() v\4<6Z:4
{ *9$SFe|&n:
.,p=e$x]
#"rK1Z
} ~=iH*AQR
K)mQcB-"?
//线程睡眠 h*C!b?:"
public static void sleep(int nSecond) )MK$E,W
{ Ze8.+Ee
try{ N'9T*&o+
Thread.sleep(nSecond); :&TM0O
} aK -x{
catch(Exception e) M @-:iP
{ u "jV#,,
e.printStackTrace (); RU4X#gP4Vh
} (@5`beEd
} (^y"'B
OVDuF&0
//日志 oV0 45G
public static void log(String sMsg) &=jPt%7#M
{ <A8>To<
System.err.println(sMsg); 6V]m0{:E
} :,aY|2si
Sk>=C0f:
!pw)sO~
public static void log(int sMsg) Vi-Ph;6[
{ f+uyO7
System.err.println(sMsg); +"<+JRI(M5
} *0^~@U
} F[Mwd &P@
fxPg"R!1i
gAdqZJR%]
/* :M6v<Kg{;
**TestMethod.java =dDPQZEin
*/ `sT;\
package NetFox; ,P`NtTN-
/CNsGx%%
?@$xLUHR4
public class TestMethod { .cQO?UKK
Wy7w zt
G/Sp/I<d
public TestMethod() n]' r3
{ ///xx/weblogic60b2_win.exe XyE$0i~t
try{ ^ZQMRNP{r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2.niB>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,GYQ,9:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6d6cZGS[:
fileFetch.start(); )wM%Ul<s
} McasnjC
catch(Exception e){e.printStackTrace ();} ;un@E:
z80P5^9
bc'IoD/
} 2wY|E<E
,.QJS6Yv
8.B'O>\T
public static void main(String[] args) }^Q:Q\
{ Mt-r`W3 q
new TestMethod(); 1l#46?]~
} j@z IJ
} HbA/~7
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