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)); _T_PX$B
} )H.ubM1
for(int i=0;i<nEndPos.length-1;i++) [f/vLLK
{ .QNjeMu.
nEndPos = nStartPos[i+1]; }k4`
} Z3Bo@`&?
nEndPos[nEndPos.length-1] = nFileLength; (/To?`
} wVlSjk
} O7!fI'R
=%:JjgKc*t
e=0l<Rj
//启动子线程 :v|r=#OI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ](]*]a4ss
for(int i=0;i<nStartPos.length;i++) $:xF)E
{ u XaL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3-4Nad
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Wdei`u[
nStartPos,nEndPos,i); iH($rSE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K]*g, s+
fileSplitterFetch.start(); *Pa2bY3:
} &n}8Uw0440
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QJ[(Y@ O6a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C]aOgt/U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ru#T^AI*^
nEndPos = " + nFileLength); l2z`<2mp
// fileSplitterFetch[nPos.length-1].start(); /e;e\k_}'
BDarJY
`;zu1o
//等待子线程结束 eTLI/?|+N
//int count = 0; 50}.Xm@,BO
//是否结束while循环 bjU 2UcI"<
boolean breakWhile = false; !&1}w86
eA3`]XP.`b
5d)'`hACe
while(!bStop) ]C9%]`
{ <K|3Q'(S
write_nPos(); ex0 kb
Utility.sleep(500); PR48~K,?
breakWhile = true; CnM+HN30o
n0Qh9*h
:u[ oc.
for(int i=0;i<nStartPos.length;i++) C5.\;;7^&
{ yffU% )
if(!fileSplitterFetch.bDownOver) ?CcR 7l
{ GapX$Jb,p
breakWhile = false; zav*
break; TmRrub
} HV#?6,U}
} O>)n*OsS
if(breakWhile) G2U5[\
break; !UUmy% 9
J)#59a
xfbK eS8
//count++; bxPY'&
//if(count>4) +ZD[[+
// siteStop(); Eg287B
} ?NL&x
I;bg?RsF
4\ uZKv@,
System.err.println("文件下载结束！"); <lg"M;&Ht
} luP'JUq
catch(Exception e){e.printStackTrace ();} )]0[`iLe
} ]4LT#
Yc. ~qmG/z
\N'hbT=
//获得文件长度 R{2GQB
public long getFileSize() "-~D!{rS
{ 5~<a>>
int nFileLength = -1; Ivd[U`=Q
try{ (;Dn%kK
URL url = new URL(siteInfoBean.getSSiteURL()); #*ZnA,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !."%M^J
httpConnection.setRequestProperty("User-Agent","NetFox"); ;f\R$u-
!ch[I#&J-
)%H5iSNG$P
int responseCode=httpConnection.getResponseCode(); B5?c'[V9
if(responseCode>=400) gMoyy
{ `-9*@_-=M
processErrorCode(responseCode); j?Jd@(*y$
return -2; //-2 represent access is error (e bBH
} .MzP}8^
0NuL9
HNkZ1+P {
String sHeader; Wq[=}qh~
47(1V/r
%~8](]p
for(int i=1;;i++) taD T;t
{ $2 +$,:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rSc,\upz
//Utility.log(in.readLine()); a?xq*|?
sHeader=httpConnection.getHeaderFieldKey(i); bH)8UQR%
if(sHeader!=null) T9XW%/n
{ J1u@A$4l?
if(sHeader.equals("Content-Length")) f)ucC$1=
{ ~(l2%(3G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CHdet(_=v
break; 1o5Y9#7
} x1&b@u
} sg9x?Bx9
else 21)-:rS
break; ^8f|clw"
} .SKNIct M
} ; ei<Q =[
catch(IOException e){e.printStackTrace ();} tc49Ty9$[
catch(Exception e){e.printStackTrace ();} j4 &
c}I8!*\
Wj f>:\w
Utility.log(nFileLength); 4Q`=t&u
_nIqy&<
4LB9w21
return nFileLength; P*"AtZuY]
} 2A18hP`^
LK-K_!F
/Mi-lh^j-
//保存下载信息（文件指针位置） 9B?t3:
private void write_nPos() GqK&'c
{ G,mH!lSm,
try{ ,N@Icl
output = new DataOutputStream(new FileOutputStream(tmpFile)); v[3hnLN%
output.writeInt(nStartPos.length); e$xv[9
for(int i=0;i<nStartPos.length;i++) !Z0rTC3d
{ r{6B+3J
// output.writeLong(nPos); 3Mh,NQB
output.writeLong(fileSplitterFetch.nStartPos); /PB3^d>Q2
output.writeLong(fileSplitterFetch.nEndPos); 61Iy{-/ZV
} gQ@Pw4bA
output.close(); 65`'Upu
} A86lyBDQ*
catch(IOException e){e.printStackTrace ();} ZjI/zqBm
catch(Exception e){e.printStackTrace ();} f)s_e
} V~uA(3\U
e2=,n6N]c
>I66R;
//读取保存的下载信息（文件指针位置） pg& ]F
private void read_nPos() ]Buk9LTe
{ *l'$pJ X
try{ /cg]wG!n8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )zc8bS
int nCount = input.readInt(); GYb2m"a)
nStartPos = new long[nCount]; T~ q'y~9o
nEndPos = new long[nCount]; >-@{vyoOy
for(int i=0;i<nStartPos.length;i++) %OfDTs
{ y\f8Ird
nStartPos = input.readLong(); *a0I Z
nEndPos = input.readLong(); >"$-VY6i
} id[>!fQ=Y
input.close(); &t%&l0
} J-%PyvK$?
catch(IOException e){e.printStackTrace ();} 4Z T
catch(Exception e){e.printStackTrace ();} '14l )1g.
} j C1^>D
4kY{X%9
aXid;v,
private void processErrorCode(int nErrorCode) &+w!'LSaD
{ d&R\7)0
System.err.println("Error Code : " + nErrorCode); 7J!d3j2TR
} t;f p<z7N.
?[4khQt
=iN_Ug+
//停止文件下载 r1[T:B'
public void siteStop() MzW$Sl&:
{ o? xR[N-J
bStop = true; bHH}x"d[x
for(int i=0;i<nStartPos.length;i++) WZ V*J&
fileSplitterFetch.splitterStop(); BaHgc 4zI
JU2' ~chh
wqoN@d
} YrcC"
} sbiDnRf
//负责部分文件的抓取 rJ~(Xu>,s
**FileSplitterFetch.java Fe2-;o
*/ HE<%d
package NetFox; r-"`Abev
4}YT@={g}
(pxz#B4
import java.io.*; Ywb)h^{!
import java.net.*; {ZYCnS&?CL
Ex&RR< 5
(i~%4w=
public class FileSplitterFetch extends Thread { D '_#?%3^
eMd1%/[
~~E=E;9
String sURL; //File URL b({b5z.A
long nStartPos; //File Snippet Start Position JI; i1@|b
long nEndPos; //File Snippet End Position 6!=9V0G~
int nThreadID; //Thread's ID qmeEUch`
boolean bDownOver = false; //Downing is over 21k-ob1Y
boolean bStop = false; //Stop identical fq!6#Usf;i
FileAccessI fileAccessI = null; //File Access interface vlKKPS
Z5^UF2`Q
X1~A "sW[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x=r6vOj
{ uRcuy/CY
this.sURL = sURL; .BTT*vL-
this.nStartPos = nStart; F"0jr7
this.nEndPos = nEnd; DppvUiQB!a
nThreadID = id; `2~Ea_Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +fR`@HI
} Xwq2;Bq
jQlK-U=oi
rG%_O$_dO
public void run() SmEd'YD!J
{ x@\'@>_GM
while(nStartPos < nEndPos && !bStop) G8c}re
{ 6Kc7@oO~
NOr*+N\
L ]'CA^N
try{ ^[NmNi*
URL url = new URL(sURL); "_}D{ws1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J_Xf:Mz-
httpConnection.setRequestProperty("User-Agent","NetFox"); T:n^$RiT
String sProperty = "bytes="+nStartPos+"-"; o;P;=<
httpConnection.setRequestProperty("RANGE",sProperty); (NV=YX?s
Utility.log(sProperty); WD1$"}R
~$obcW1
-Af`AX
InputStream input = httpConnection.getInputStream(); @8d})X33
//logResponseHead(httpConnection); '(:J|DN
13@| {H CB
! yUKNR
byte[] b = new byte[1024]; _NN{Wk/3w
int nRead; P@![P Ij
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,Yt&PE
{ *Bz&
nStartPos += fileAccessI.write(b,0,nRead); g2_df3Q
//if(nThreadID == 1) P9!]<so
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Q(I&uz
} 4f~ZY]|nM
)_ u'k /
J}u1\Id%
Utility.log("Thread " + nThreadID + " is over!"); \ku{-^7
bDownOver = true; AlhiF\+ C
//nPos = fileAccessI.write (b,0,nRead); ZDD|MH
} 3"%44'
catch(Exception e){e.printStackTrace ();} xeh|u"5
} TzXl ?N
} vwD(J.;
|*a>6y
^%@.Vvz<
//打印回应的头信息 ?wY.B
public void logResponseHead(HttpURLConnection con) gJv^v`X
{ )ciHY6
for(int i=1;;i++) Oz7v hOU
{ 1 niTkop
String header=con.getHeaderFieldKey(i); #-,`4x$m|
if(header!=null) GlZDuU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e28#Yh@U
Utility.log(header+" : "+con.getHeaderField(header)); RuuU}XQ
else wfzb:Aig`
break; ]<= t
} sVnuSm
} 0g)mf6}o
g?M69~G$:x
r!uAofIi_
public void splitterStop() &|;!St]!M
{ GTe9@d
bStop = true; ".Ug A\0
} S5!2%-;<k
)Ggx
gJ7puN
} o(qmI/h
"j>0A Hem
\H(,'w7H
/* +[DVD
**FileAccess.java gk`.8o
*//文件访问(定位，写) ugP R)tDfM
package NetFox; ?A>-_B
import java.io.*; *k$&Hcr$
i9"1
95&HsgdxJ
public class FileAccessI implements Serializable{ ']D( ({%g
8hT>)WH}wo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LlqhZetS
RandomAccessFile oSavedFile; .&dcJh*O+
long nPos; fok#D>q
K-5)Y+| >
&x #5-O'
public FileAccessI() throws IOException >?KyPp
{ KS_d5NvYl
this("",0); 8uiQm;W
} PGGJpD?
JTJ4a8DE
mt'#j"mU
public FileAccessI(String sName,long nPos) throws IOException "k/@tX1:R
{ 'fsOKx4Z
oSavedFile = new RandomAccessFile(sName,"rw"); ".4^?d_^VF
this.nPos = nPos; rz*Jmn b
oSavedFile.seek(nPos); Ek0.r)Nw
} {n'}S(
M}u2aW2]X
/2q%'"x(
public synchronized int write(byte[] b,int nStart,int nLen) 3]P=co@
{ [u:_Jqf-
int n = -1; |Gi/=[Tp
try{ 7;{F"/A
oSavedFile.write(b,nStart,nLen); gy.; "W
n = nLen; 7Jk.U=vY
} {`> x"Y5
catch(IOException e) x1h!_^(QfF
{ =JkSq J)?
e.printStackTrace (); T /uu='3
} i%2K%5{)$D
:08UeEy
Iq*7F5B
return n; *XuzTGa"
} 9Wn0YIc
VM`."un]
,D1QJPM
} |HLh?AcX
C{-pVuhK+
3@PVUJ0B|
/* Kt(p|
**SiteInfoBean.java z,WrLZC
*/ paY%pU
package NetFox; @z.!Dby
t{9Ph]e
r%4:,{HF
public class SiteInfoBean { "P~>AXcq
.755-S
M=%p$\x
private String sSiteURL; //Site's URL 6._):[_2
private String sFilePath; //Saved File's Path .jU9{;[
private String sFileName; //Saved File's Name H b.oKo$T
private int nSplitter; //Count of Splited Downloading File bmLNR
.1;?#t]ZV
9z#IdY$a
public SiteInfoBean() 0Sk{P>A
{//nSplitter的缺省值为5 Sl1N V
//default value of nSplitter is 5 Lfor0-j
this("","","",5); cQjJ9o7
} 23PSv8;EM
{#MViBhd%
xUYSD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0#G"{M
{ TocqoYX{{
sSiteURL= sURL; k6XO-a f
sFilePath = sPath; X'Oo ogu
sFileName = sName; 2B#\683
this.nSplitter = nSpiltter; UOyP6ej
U4gZW]F
`#hy'S:e
} 2mRso.Ah
B(~D*H2T[
9I9)5`d|Jn
public String getSSiteURL() Ua4} dW[w
{ 1D$k:|pP~
return sSiteURL; &nq[Vy0kO4
} ^,3 >}PU
.s+e hZ
Ur@3_F
public void setSSiteURL(String value) =o {`vv
{ j>U.(K
sSiteURL = value; ~vgW:]i
} *UTk. :G5
<NUZPX29
cWi2Sls
public String getSFilePath() mEA w^
{ uQDu<@5^[
return sFilePath; NJ~'`{3v
} 0o#lB^e;l
5v]xk?Eb
6-oQs?
public void setSFilePath(String value) ` H"5nQRV
{ <rkF2-K,
sFilePath = value; >U17BGJ.
} (HEjmQjE
|:AjQ&PM)
T@L^RaPX
public String getSFileName() ?h5Y^}8Qg
{ wz ,woF|
return sFileName; ]2<g"zo0
} ~=71){4A
fRbVc
o,d:{tt
public void setSFileName(String value) 90q*V%cS
{ [wExjLW
sFileName = value; *Q)+Y&qn
} $u P{,ML
+ 7Z%N9
x@/!H<y
public int getNSplitter() S+He
{ SXhJz=h
return nSplitter; vK$W)(Z
} ^t| %!r G
cD 1p5U
$HaM, Oh;i
public void setNSplitter(int nCount) WA<~M)rb
{ 4)`{ L$
nSplitter = nCount; Aam2Y,B
} v>,XJ7P
} % $J^dF_0
-v]7}[ .[
Q>|<R[.7
/* V Bg$r[
**Utility.java p4/D%*G^`
*/ Ft07>E$/Q^
package NetFox; 0g1uM:;
]`lTkh
O)hNHIF
public class Utility { iM\W"OUl[
8r~4iVwg
rtPQ:CaA)?
public Utility() {3l]/X3
{ v +7<}
a{y;Ub
P:Bg()
} /u?^s "C/
n|8fdiK#}
//线程睡眠 /m%;wH|6%
public static void sleep(int nSecond) +Ix;~
{ OH&&d=~
try{ 1vX97n<}
Thread.sleep(nSecond); YM5;mPR
} qLcs)&}/A
catch(Exception e) F&ux9zP
{ 3t8VH`!mL{
e.printStackTrace (); 1%>/%eyn5
} -&+[/
} VLRW,lR9O
.8k9yk
//日志 O5E\#*<K
public static void log(String sMsg) u-8,9
{ tYVmB:l
System.err.println(sMsg); pJV<#<#Z
} ;0 ,-ywK
]@_*O$
/CH*5w)1
public static void log(int sMsg) 6z~6o0s~
{ L9@nx7D
System.err.println(sMsg); *S7<QyVh
} p2\@E} z
} aCQAh[T
"I u3&mc
-_B*~M/vV`
/* &kh-2#E
**TestMethod.java <"6}C)G
*/ [V =O$X_
package NetFox; G/b $cO}
'?4B0=
"HlT-0F
public class TestMethod { 1a`dB ~>
rxt)l
?nE<Aig
public TestMethod() uq'T:d
{ ///xx/weblogic60b2_win.exe A3MVNz$wo"
try{ 86oa>#opU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JT!-Q!O}O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ww:,O48%
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ju# - >]
fileFetch.start(); Z!DGCw
} ).5$c0`U&
catch(Exception e){e.printStackTrace ();} 54v}iG
y$'(/iyz
ApR>b%
} *{6{ZKM
xO{yr[x"L
5*C#~gd&F
public static void main(String[] args) it \3-
{ oUoDj'JN{
new TestMethod(); yHe%e1
} HZKqGkE
} :A"GOc,
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