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)); ?o_D#gG*
} ,{sCI/
for(int i=0;i<nEndPos.length-1;i++) CChCxB
{ *"sDsXo- I
nEndPos = nStartPos[i+1]; ="s>lI-1a
} YHI@Cj
nEndPos[nEndPos.length-1] = nFileLength; pLsJa?}R
} @H|3e@5([
} }+BbwBm&
z?Qt%1q
P*{*^DN
//启动子线程 9+co`t.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZvkBF9d
for(int i=0;i<nStartPos.length;i++) {WN??eys,
{ wj|[a,(r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >UBozmF=\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _rfGn,@BH
nStartPos,nEndPos,i); 2qDVAq^@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ( 2i{8
fileSplitterFetch.start(); Y1L7sH 9
} 0 A6%!h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7A4_b8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K5:>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .u&GbM%Ga
nEndPos = " + nFileLength); [TX5O\g![
// fileSplitterFetch[nPos.length-1].start(); /PgcW
^:,I #]
[h~#5x
//等待子线程结束 T|ZJ$E0
//int count = 0; o7t#yw3
//是否结束while循环 }XIUz|
boolean breakWhile = false; ^3w >:4m
rWxQ;bb#
75RQ\_zDu
while(!bStop) Hy#<fKz`!
{ P> ilRb
write_nPos(); .dl4f"k
Utility.sleep(500); `Y.Q{5Y
breakWhile = true; ~"i4"Op&
cA25FD
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for(int i=0;i<nStartPos.length;i++) F;<cG`|Rx
{ 4%,E;fB?=
if(!fileSplitterFetch.bDownOver) ~+bSD<!b
{ P|kfPohI=
breakWhile = false; nZ~J&QK-
break; >e9xM Gv
} gukKa
} 4: S-
if(breakWhile) a29rD$
break; +G[N lb
Nm,9xq
88M$mjx
//count++; 6@cT;=W;xj
//if(count>4) Zh3hCxXa
// siteStop(); }pL#C
} a^.5cJ$]
f)%8*B
_Sn7z?
System.err.println("文件下载结束！"); ~t.M!vk
} 7&{[Y^R]"
catch(Exception e){e.printStackTrace ();} D+69U[P_A
} 8^av&u$
5_= HtM[v]
E>3(ff&
//获得文件长度 A]q"+Z]
public long getFileSize() "`aLSw75x
{ R[{s\
int nFileLength = -1; (| X?
try{ tP]-u3
URL url = new URL(siteInfoBean.getSSiteURL()); R[_UbN 28
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >(39K
httpConnection.setRequestProperty("User-Agent","NetFox"); QzX|c&&>u2
y%=t((.Z
Cz]NSG5
int responseCode=httpConnection.getResponseCode(); )%=oJ!)
if(responseCode>=400) Q R<q[@)F
{ 4l`"P~=2<
processErrorCode(responseCode); .Pi8c[
return -2; //-2 represent access is error k\`~v$R3
} "L~qsFL
sQ>L3F;A`
~(/OB w
String sHeader; F)^:WWVc#
?Z[`sm
>{huaN B
for(int i=1;;i++) ew{(@p+$
{ B0#JX MX9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (2fWJ%7VG
//Utility.log(in.readLine()); Rw#4 |&
sHeader=httpConnection.getHeaderFieldKey(i); c2d=dGP>~f
if(sHeader!=null) Hj^_Cp]@*
{ y7WO:X&
if(sHeader.equals("Content-Length")) Aq:1
{ `UDB9Ca
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D4e!A@LJ
break; <u%&@G$F>
} 5 Yf T
} _"R /k`8
else A6#5 z
break; 1Xj>kE:
} ^ ;XJG9a0\
} ?7"6dp_K
catch(IOException e){e.printStackTrace ();} =w <;tb
catch(Exception e){e.printStackTrace ();} sGs_w:Hn
Y}Gf%Xi,
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Utility.log(nFileLength); |Xv]s61
$m)[> C
^CWxYDG*
return nFileLength; c1L0#L/F6"
} % A8dO+W
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0.}WZAYy~
//保存下载信息（文件指针位置） smTPca)7s
private void write_nPos() hxQx$
{ JXA!l?%
try{ !<2%N3l
output = new DataOutputStream(new FileOutputStream(tmpFile)); Mp`2[S@$
output.writeInt(nStartPos.length); TowRY=#jiS
for(int i=0;i<nStartPos.length;i++) ! >l)*jN8
{ V$';B=M
// output.writeLong(nPos); ir/-zp_
output.writeLong(fileSplitterFetch.nStartPos); s8 c#_
output.writeLong(fileSplitterFetch.nEndPos); WY 'QhieH
} F.[E;gOTo
output.close(); q"O4}4`
} zEYT,l
catch(IOException e){e.printStackTrace ();} mxQPOu
catch(Exception e){e.printStackTrace ();} >^5UXQr
} Bc^MZ~+ip
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mM6X0aM
//读取保存的下载信息（文件指针位置） i{+W62k*
private void read_nPos() Sdn4y(&TP
{ Td"_To@jd
try{ "cVJqW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K~DQUmU@
int nCount = input.readInt(); 7g&"clRGO
nStartPos = new long[nCount]; oPCtLz}z
nEndPos = new long[nCount]; x'IYWo ]
for(int i=0;i<nStartPos.length;i++) (_aM26s
{ gJUawK
nStartPos = input.readLong(); ndCHWhi
nEndPos = input.readLong(); *[SOz)
} [x\?._>
input.close(); ,KyG^;Riy
} :G\X
catch(IOException e){e.printStackTrace ();} K.T.?ug;:
catch(Exception e){e.printStackTrace ();} GjD^\d/
} i SD?y#
)J<VDO:_YA
V+'C71-P
private void processErrorCode(int nErrorCode) DN%b!K:
{ pni*#W*n
System.err.println("Error Code : " + nErrorCode); @W+m;4HH
} /3`(Ki{ Q
q{:]D(
nhZ^`mP
//停止文件下载 v3q.,I_
public void siteStop() nS5g!GYY,k
{ b|KlWt'
bStop = true; f0d*%
for(int i=0;i<nStartPos.length;i++) }mx>3G{d
fileSplitterFetch.splitterStop(); p|f5w"QcH
)=]u]7p}
-cL{9r&X
} &}q;,"
} 6*uWRjt
//负责部分文件的抓取 e"@Ag:r@a
**FileSplitterFetch.java xP61^*-2
*/ $9%UAqk9
package NetFox; @cC@(M~Ru
9H6%\#rw
6hX[5?}
import java.io.*; {/E_l
import java.net.*; CqkY_z
@7j$$
sJ !<qb5!
public class FileSplitterFetch extends Thread { .WV5Gf)
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nA)KRCi
String sURL; //File URL [d^ [Y:I'\
long nStartPos; //File Snippet Start Position \lBY4j+;
long nEndPos; //File Snippet End Position ]XS[\qo
int nThreadID; //Thread's ID 3UX/
boolean bDownOver = false; //Downing is over 4?2$~\ x
boolean bStop = false; //Stop identical }3DZ`8u
FileAccessI fileAccessI = null; //File Access interface abgAUg)
X<*-d6?gD`
L63B# H"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s-"oT=
{ (l]_0-Z
this.sURL = sURL; zS<idy F`
this.nStartPos = nStart; px>g
this.nEndPos = nEnd; #x|IEjoa
nThreadID = id; 7~2c"WE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E-?@9!2 &
} ~qu}<u)P
/ho7O/aAa
;T,`m^@zf
public void run() A/A;'9
{ +{dJGPoY]p
while(nStartPos < nEndPos && !bStop) T_NN.Ol
{ qvN`46c
aWTvowA
Hph$Z1{
try{ k0^t$J W
URL url = new URL(sURL); P3op1/Np
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +F@ZVMp
httpConnection.setRequestProperty("User-Agent","NetFox"); I/`\>Hk
String sProperty = "bytes="+nStartPos+"-"; *ud/'HR8]
httpConnection.setRequestProperty("RANGE",sProperty); t8_i[Hw6D
Utility.log(sProperty); )~LqBh
>9i%Yuy](
l/6$BPU`
InputStream input = httpConnection.getInputStream(); t[=teB v<
//logResponseHead(httpConnection); %SKJ#b
S #6:!
d:{#Dk#
byte[] b = new byte[1024]; l1uv]t <
int nRead; H5X.CcI&}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r t\eze_5A
{ "IuPg=|#
nStartPos += fileAccessI.write(b,0,nRead); 8d|#W
//if(nThreadID == 1) +txHj(Y`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U%u%_{-
} Q35jJQ$<`
$dkkgsw7
cOrFe;8-.
Utility.log("Thread " + nThreadID + " is over!"); )gPkL r
bDownOver = true; m!LJK`gA
//nPos = fileAccessI.write (b,0,nRead); :vo#(
} C $*#<<G
catch(Exception e){e.printStackTrace ();} Ds@nuQ
} qx2M"uFJ
} ? e<D +
rcU*6`IWA
\l71Q/y6u`
//打印回应的头信息 /&!4oBna
public void logResponseHead(HttpURLConnection con) 6)j/"9oY
{ qfS ]vc_N
for(int i=1;;i++) *)xjMTJ%
{ dQ`=CIr
String header=con.getHeaderFieldKey(i); (_Ky'.
if(header!=null) 1!p7N$QR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4KnrQ-D
Utility.log(header+" : "+con.getHeaderField(header)); CEl9/"0s6
else j&w4yY
break; o|bm=&f
} FQqk+P!
} V PaW-o
a*bAf'=
Su*f`~G];
public void splitterStop() 6!$2nK+
{ bv9nDNPD4
bStop = true; JSu+/rI1
} z( ^ r
:V ZXI#([
Z,JoxK2"
} E9~}%&
X|Rw;FY
4ztU) 1
/* \Jm^XXgS
**FileAccess.java 0$:jZ/._
*//文件访问(定位，写) (pT7m
package NetFox; r9y(j z
import java.io.*; UtYwG#/w
U C..)9
`FHKQS5
public class FileAccessI implements Serializable{ L,_Z:\^
k r ga!,I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )Nnrsa
RandomAccessFile oSavedFile; xjH({(/B>a
long nPos; H-/w8_} KG
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Y@2v/O,\
public FileAccessI() throws IOException ;Yu|LaI\<m
{ s~g0VNu Y
this("",0); R@A"U[*
} R>y/Y<5=
g\Akf
SK t&BnW
public FileAccessI(String sName,long nPos) throws IOException Mi:i1i cdn
{ v18OUPPX
oSavedFile = new RandomAccessFile(sName,"rw"); qj1Fj
this.nPos = nPos; 1dl(`=^X
oSavedFile.seek(nPos); 9`T2
} qLa6c2o,
yP0XA=,Y
v]c+|nRs
public synchronized int write(byte[] b,int nStart,int nLen) I08W I u
{ u`Abko<D
int n = -1; u5rHQA0%
try{ \Y^GA;AMQQ
oSavedFile.write(b,nStart,nLen); "a=dx| Z
n = nLen; 6S&OE k
} m,^UD{
catch(IOException e) X-j3=8wPM
{ @@"abhT
e.printStackTrace (); xM2UwTpW
} +~\1g^h
G6q*U,
O*udVE>
return n; 6~tj"34_
} *_H^]wNJG
aK?PK }@
$*c!9Etl4
} MwTouEGGgA
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DT[WO_=
/* |oX1J<LM
**SiteInfoBean.java o[B"J96b
*/ O~4Q:#^c
package NetFox; /0(c-Dv
BNq6dz$J
;X%8I$Ba,
public class SiteInfoBean { -fT}Nj\
7_CX6:
5 [X,?
private String sSiteURL; //Site's URL V#TNv0&0
private String sFilePath; //Saved File's Path Z7J4rTA
private String sFileName; //Saved File's Name Xz\X 8I
private int nSplitter; //Count of Splited Downloading File pIl[)%F
]6@6g>f?
Q3rLCg,;
public SiteInfoBean() ]/{iIS_
{//nSplitter的缺省值为5 V@pUU~6R
//default value of nSplitter is 5 K:54`UJ
this("","","",5); v(~EO(n.
} o(eh.
_|wnmeL*
04#<qd&ob@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tl L\&n.$
{ j|%>NB ):
sSiteURL= sURL; 3,)[Q?nKD
sFilePath = sPath; q_z;kCHM
sFileName = sName; 6[\1Nzy>
this.nSplitter = nSpiltter; =k##*%
vY);7
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} 79Ur1-]/
vf?Xt
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public String getSSiteURL() bwe)_<c
{ 9v?rNJs
return sSiteURL; }#phNn6
} R#4f_9e<Z
~WKWx.ul
Q& S 7_
public void setSSiteURL(String value) ]e(\<R6Gf
{ <$Djags,F
sSiteURL = value; kJpr:4;@_
} UL]zuW/
}gKY_e3
Xa_:B\ic
public String getSFilePath() bJ^Jmb
{ lu;gmWz
return sFilePath; *3rp g
} N9 TM
gf70 O>E
)WsR 8tk
public void setSFilePath(String value) +2g}wH)l
{ SXx4^X
sFilePath = value; rm4t
} V(;c#%I2
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+do*C=z
public String getSFileName() X3HJ3F;==
{ %J+k.UrM
return sFileName; 8^!ib/@v"
} 1pP q)}=+
!*PX-
N5mhs#
public void setSFileName(String value) EOXuc9>G
{ [~ !9t9+~
sFileName = value; W4"1H0s`l
} )!=fy']
u3\_![Jt?
?f:ND1jU
public int getNSplitter() J|CCTXT
{ 3{M0iNc1
return nSplitter; .p%V]Ka
} O)c3Lm-w
o.wXaS8
z`sW5K(A
public void setNSplitter(int nCount) f('##pND@
{ BO0Y#fs
nSplitter = nCount; K0Lc~n/
} `d4;T|f+=
} MbeK{8~E%l
Z/LYTo$Bz
9Us'Q{CD
/* vdd>\r)v
**Utility.java [a7S?%>Bh
*/ j43i:c;F
package NetFox; rh T!8dTk
74a k|(!
M$e$%kPShE
public class Utility { #M<u^$Jz
!}q@O-}j
AmK g;9LS
public Utility() k#G+<7c<
{ *~^%s+b
5")BCA
d>wG6Z,|
} :3D[~-/S
99~ZZG
//线程睡眠 Si68_]:^
public static void sleep(int nSecond) n/^QPR$>.
{ A_+*b [P
try{ R)Dh;XA
Thread.sleep(nSecond); o<rbC < U
} !L)yI#i4C
catch(Exception e) `+(4t4@ew
{ 7e /Kh)5G
e.printStackTrace (); VM+l9z>
} }]. |7h
} 0G3T.4I
EGjzjuJu{
//日志 AjINO}b
public static void log(String sMsg) !X 0 (4^
{ zKGr(9I
System.err.println(sMsg); Kr%`L/%
} ).jna`A,
/Q'O]h0a
2ZKy7p0/
public static void log(int sMsg) :-~x~ah-
{ y2Vc[o(NP
System.err.println(sMsg); Fl++rUT
} p<&dy^mS
} N|w;wF!3
Rk}=SB-
M] W5%3do
/* xI8v'[3
**TestMethod.java e*o:ltP./
*/ P7!gUxcv9Y
package NetFox; \>+BvF
Jo9c|\4
PRK*7-(
public class TestMethod { EC?U#!kv
BXr._y, cr
s"l ^v5
public TestMethod() F>at^6^
{ ///xx/weblogic60b2_win.exe ]CgZt'h{
try{ :U-yO 9!j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uN6xOq/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #J%Fi).^)
SiteFileFetch fileFetch = new SiteFileFetch(bean); [Rzn>
fileFetch.start(); [}y"rs`!
} kLbo |p"cT
catch(Exception e){e.printStackTrace ();} h|ja67VG
@@|H8mP}H
3Ael
} %j?7O00@
>c.HH}O0W
l6!a?C[2T
public static void main(String[] args) r`C t/]c
{ XNkQ0o0
new TestMethod(); 7` t,
} ? \NT'CG
} E9j(%kQ2
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