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)); =gSc{ i|
} D~"a"
for(int i=0;i<nEndPos.length-1;i++) VOr:G85*s
{ ~tfd9,t
nEndPos = nStartPos[i+1]; 3s%DF,
} ef7 U7
nEndPos[nEndPos.length-1] = nFileLength; "aKlvK:77
} FYFlh^}
} >%`SXB&9
N}nE9z5
O&/nBHu\
//启动子线程 BhAT@%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2 ^"j]g>mj
for(int i=0;i<nStartPos.length;i++) ,(h-
{ -?#iPvk6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o9| OL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z}0{FwW"4
nStartPos,nEndPos,i); M .6BFC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qZ>_{b0f
fileSplitterFetch.start(); -!7Z
} HTiLA%%6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {9|*au(K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;|XX^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MXl_{8
nEndPos = " + nFileLength); ML|?H1m>
// fileSplitterFetch[nPos.length-1].start(); UZFs]z!,k
O95gdxc
i^:#*Q-co
//等待子线程结束 a8)2I~j
//int count = 0; ]Zh$9YK
//是否结束while循环 M __S)
boolean breakWhile = false; FsOJmWZ
w3 vZ}1|
1l)j(,Zd*
while(!bStop) 7&P70DO
{ yy/'B:g
write_nPos(); Jjj;v2uSK
Utility.sleep(500); Ppl :_Of
breakWhile = true; j|[$P4w}U
3r[F1z2B
V[%IU'{:
for(int i=0;i<nStartPos.length;i++) 6`'g ${U
{ Q'^'G>MBJ
if(!fileSplitterFetch.bDownOver) aJ=)5%$6kc
{ q0ab]g+
breakWhile = false; cyd&bxPgj+
break; C=Fu1Hpb
} k1g-%DB
} l%Ke>9C
if(breakWhile) R*cef
break; W.{+0xx
_0u=}tc
JT<JS6vw#
//count++; 'tkQz
//if(count>4) MaPhG<?
// siteStop(); @6~m&$R/
} ;,]4A{|
k9H}nP$F
qB@N|Bb
System.err.println("文件下载结束！"); $;=^|I4E
} ktfxb<%
catch(Exception e){e.printStackTrace ();} J3oUtu
} Ux^ue9
{I0!q"sF
&.2%p
//获得文件长度 5G'2 Wby'#
public long getFileSize() a(fiW%eFb
{ Vr& GsT
int nFileLength = -1; >mvE[iXRG?
try{ .%J<zqk-
URL url = new URL(siteInfoBean.getSSiteURL()); v0\M$@N[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E*T6kp^b
httpConnection.setRequestProperty("User-Agent","NetFox"); DsxNg
|*ZM{$
v0&DD&mp
int responseCode=httpConnection.getResponseCode(); :0%[u(
if(responseCode>=400) dj] O
{ ^Ar1V!PFk
processErrorCode(responseCode); D` cy.},L
return -2; //-2 represent access is error 5IzCQqOPgX
} T,/<'cl"
;^E\zs
l_04b];
String sHeader; ;mD!8<~z.
KU/QEeqbrp
P^Og(F8;
for(int i=1;;i++) %sZ3Gpi
{ 8N j}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _(=g[=Mer
//Utility.log(in.readLine()); H9BqE+
sHeader=httpConnection.getHeaderFieldKey(i); ]o'dr r
if(sHeader!=null) G]xN#O;
{ p[|V7K'Z
if(sHeader.equals("Content-Length")) >#S}J LZ
{ 7|Wst)_~j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]3]B$
break; .8'uIA{_2
} 32j#kJW
} 9ec#'i=
else 5xUZeLj
break; ey<z#Q5+
} 2Nm{.Y
} 2C"i2/NH'
catch(IOException e){e.printStackTrace ();} c?c"|.-<p
catch(Exception e){e.printStackTrace ();} x)%"i)
*<{hLf
&Nr+-$
Utility.log(nFileLength); 1p/_U?H:|
d"3x11|
$*XTX?,'
return nFileLength; S:g6z'e1
} L1k
l%i*.b(
-c0*
//保存下载信息（文件指针位置） e&(Wn2)o
private void write_nPos() KF#qz2S
{ rnMi >?
try{ +WR'\15u
output = new DataOutputStream(new FileOutputStream(tmpFile)); :zfMRg
output.writeInt(nStartPos.length); RcR-sbR
for(int i=0;i<nStartPos.length;i++) D&N3LH
{ vgNrHq&2q
// output.writeLong(nPos); h^WMv *2
output.writeLong(fileSplitterFetch.nStartPos); ]w-W
output.writeLong(fileSplitterFetch.nEndPos); +-V4:@
} mMu+MXTk<
output.close(); IK4(r /
} F2n4#b
catch(IOException e){e.printStackTrace ();} 6khm@}}
catch(Exception e){e.printStackTrace ();} W8]?dL}|
} Qe9}%k6@E
7<8'7<X
j\BtaC
//读取保存的下载信息（文件指针位置） `X&d:!}F
private void read_nPos() -@'RYY=
{ %vG;'_gMB
try{ YD~(l-?"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &d!ASa
int nCount = input.readInt(); >N~jlr|
nStartPos = new long[nCount]; pZc`!f"
nEndPos = new long[nCount]; PCBV6Y7r
for(int i=0;i<nStartPos.length;i++) m60hTJ?N)
{ ^6CPC@B1
nStartPos = input.readLong(); axXR-5c
nEndPos = input.readLong(); ;'!h(H
} I[06R
input.close(); kMa|V0
} ^}z:FI
catch(IOException e){e.printStackTrace ();} /Vv)00
catch(Exception e){e.printStackTrace ();} ~(rZ)
} {@" F/G+
g'-hSV/@}@
tM:$H6m/(
private void processErrorCode(int nErrorCode) S =sL:FC
{ ZM=eiJZ
System.err.println("Error Code : " + nErrorCode); v,3}YDu
} oO;<$wx2t
pBu}c<
~dsx|G?p
//停止文件下载 [H`5mY@
public void siteStop() ${t$:0R,h
{ ]jmZ5h#[
bStop = true; ,mD$h?g
for(int i=0;i<nStartPos.length;i++) PDh!B_+
fileSplitterFetch.splitterStop(); [S.zWPX9{
p5nrPL
tKi^0vE8
} <V8=*n"mR
} qV$0 ";d
//负责部分文件的抓取 %we! J%'Y]
**FileSplitterFetch.java ;O .;i,#Z
*/ =NRiro
package NetFox; Tkh?F5l
dTU`@!f
(b.Mtd
import java.io.*; lqoVfj'6M
import java.net.*; w-wJhc|
(Y?}'?
w/fiNY5FZ
public class FileSplitterFetch extends Thread { LA,G>#?H
Q#4OgNt
qyBo|AQ5
String sURL; //File URL *^\u%Ir"
long nStartPos; //File Snippet Start Position Vgj[m4l
long nEndPos; //File Snippet End Position 1!ijRr
int nThreadID; //Thread's ID aU] nh. a
boolean bDownOver = false; //Downing is over c 8|&Q
boolean bStop = false; //Stop identical 0gKSjTqo
FileAccessI fileAccessI = null; //File Access interface ~Z97L
R"71)ob4
vrsOA@ee3H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pD6a+B\;k
{ '&y+,2?;Y[
this.sURL = sURL; rAu@`H?
this.nStartPos = nStart; \#'m([<e
this.nEndPos = nEnd; hl+ T
nThreadID = id; 1~*JenV-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wA%,_s/U
} dM5N1$1,
QnH~' k
I9cZZ`vs
public void run() ~0{F,R.$
{ vqwSOh|P9
while(nStartPos < nEndPos && !bStop) #X<s_.7DJ
{ )-LSn
ZV:0:k.x
(ZK(ODn)i
try{ Biy$p6
URL url = new URL(sURL); `lE8dwL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L?hWH0^3
httpConnection.setRequestProperty("User-Agent","NetFox"); }RkD7
String sProperty = "bytes="+nStartPos+"-"; x#tP)5n?s*
httpConnection.setRequestProperty("RANGE",sProperty); &PEw8: TX
Utility.log(sProperty); eJZt&|7N
)G$0:-J-
M7AUY#)
InputStream input = httpConnection.getInputStream(); ::k/hP9.^
//logResponseHead(httpConnection); sHMZ'9b
H|B4.z
-<n]Sv;V
byte[] b = new byte[1024]; '.tg\]|
int nRead; H?'t>JX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U\tujK1
{ )u5+<OG}=
nStartPos += fileAccessI.write(b,0,nRead); PPj0LFA
//if(nThreadID == 1) f.u+({"ql
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^Hv4t
} m[?gN&%nc
Vg? 1&8>
8Jf4";
Utility.log("Thread " + nThreadID + " is over!"); -$kAWP8P4
bDownOver = true; Hz3KoO &
//nPos = fileAccessI.write (b,0,nRead); *8xMe
} 1"} u51
catch(Exception e){e.printStackTrace ();} 8|\?imOp\[
} t9m08K:Y
} H5p&dNO
g=n /w
=xsTVT;sj
//打印回应的头信息 8u#2M8.5E
public void logResponseHead(HttpURLConnection con) [e`6gGO
{ THDyb9_g
for(int i=1;;i++) EEO)b_(
{ U>kL|X3 V
String header=con.getHeaderFieldKey(i); *`wgqin
if(header!=null) A;C)#Q/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G8!* &vR/
Utility.log(header+" : "+con.getHeaderField(header)); c7(Lk"G8
else YST{ h{
break; yixAG^<
} G![JRJxQ
} yj C@
:/'oh]T|
+HNM$yp
public void splitterStop() $/;;}|hqi
{ InR/g@n+D1
bStop = true; "E )0)A3=
} !%%(o%bi~
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+OC~y:
} Q!G^CG
6'1m3<G_
XhG3Of-6
/* B1Cu?k);.
**FileAccess.java %.VFj7J
*//文件访问(定位，写) ?mJ&zf|B8
package NetFox; h1.<\GO
import java.io.*; ORP-@-dap
^26}j uQ
dw]jF=u
public class FileAccessI implements Serializable{ 1=Nh<FuQ
s+OXT4>+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VgyY7INx9
RandomAccessFile oSavedFile; xl4A<
long nPos; M|xs>+r*
bL]NSD
wPrqFpf
public FileAccessI() throws IOException XPQY*.l&.
{ o6T'U#7P
this("",0); ;o-c.-!F
} Th>ff)~e
]XhX aoqL
@UCr`>
public FileAccessI(String sName,long nPos) throws IOException .bvEE
{ /@QPJ~%8Ud
oSavedFile = new RandomAccessFile(sName,"rw"); @m+2e C77
this.nPos = nPos; >#~>!cv6D
oSavedFile.seek(nPos); JOFQyhY0>m
} s2*~n_B
)LDBvpJyQ
#4BwYj(Sl
public synchronized int write(byte[] b,int nStart,int nLen) AMf{E
{ qe<aJn
int n = -1; j;SK{Oq
try{ ykat0iqo
oSavedFile.write(b,nStart,nLen); _-5|"oJ
n = nLen; 5~GH*!h%;
} BOdd~f%&tn
catch(IOException e) Zb}U 4
{ !THa?U;
e.printStackTrace (); ~ NZC0&
} :^H2D=z@
(utk)
<kOdd)X
return n; 7*\CfqrU
} 5/YGu=,
!hWS%m@
hh7unHt-
} *!m(oP
7tQ?av
dwJnPJ=z
/* n4InZ!)
**SiteInfoBean.java /?Hq
*/ Aa4 DJ
package NetFox; Xb2.t^ ]f
>0E3Em<(}l
R@~=z5X(Q
public class SiteInfoBean { s((c@)M
B]u!BBjC
+;/ s0
private String sSiteURL; //Site's URL _qa9wK/
private String sFilePath; //Saved File's Path 7Fzj&!>ti
private String sFileName; //Saved File's Name `G:I|=#w
private int nSplitter; //Count of Splited Downloading File [P*zm8b
{4eI}p<
~@mNR^W-W
public SiteInfoBean() EslHml#
{//nSplitter的缺省值为5 "</A)y&
//default value of nSplitter is 5 @Nn'G{8OG
this("","","",5); *I.eCMDa
} EGVS8YP>h
%l[]n;*$
>S>B tRl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lk.Mc6)
{ moRo>bvN~
sSiteURL= sURL; MO%+rf0~w
sFilePath = sPath; \+j:d9?
sFileName = sName; 5Nl?Km~
this.nSplitter = nSpiltter; '*D>/hn|:]
Q zp!)i
$Y M(NC
} ipyc(u6Z5
xnxNc5$oE
e$7KMH=
public String getSSiteURL() Je4hQJ<h
{ +GncQs y
return sSiteURL; -"rANP-UI
} .d6b?t
&v#pS!UOj
Va[t'%~&zR
public void setSSiteURL(String value) Y`."=8R~
{ ^l<!:SS
sSiteURL = value; T:SqENV
} DMOP*;Uk
3$S~!fh
.03Rp5+v
public String getSFilePath() C3'?E<F
{ a$\Bt_
return sFilePath; 1Tr%lO5?6
} "'C5B>qO
>pp#>{}
c dWg_WBC
public void setSFilePath(String value) s bd$.6 |&
{ qeb}~FL"o
sFilePath = value; G[6i\Et
} T;]Ob3(BpW
eV~"T2!Sb
(\'$$
public String getSFileName() n5z|@I`S_
{ 6AoKuT;
return sFileName; \}~71y}
} [.}Uzx
K>C@oE[W
m2P&DdN[
public void setSFileName(String value) @1xIph<z
{ L6#4A3yh
sFileName = value; &;~?\>?I
} 3.1%L"r[)
fzA Fn$[
_zJ /z
public int getNSplitter() e)N<r
{ :K5?&kT
return nSplitter; +prUau*
} ns*:mGh
MkhD*\D /
)+DDIq
public void setNSplitter(int nCount) w!z*?k=Da
{ X%iJPJLza
nSplitter = nCount; K7@|2;e
} JPHM+3v
} =z]rZSq*o
&H P g>
|sY
/* )0DgFA6k_
**Utility.java q#SEtyJL
*/ 3=^)=yOd
package NetFox; bWSc&/9y
BzS\p3&
(> _Lb
public class Utility { !dUdz7
#C~ </R%
K&zW+Cb
public Utility() KVr9kcs
{ ijUu{PG`X
SM%/pu;
,RM8D)m\
} ~( 0bqt3c
4w#2m>.
//线程睡眠 P3n#s2o6y
public static void sleep(int nSecond) ij!],
{ Jm#p!G+
try{ LokH4A17U
Thread.sleep(nSecond); ?qi~8.<w
} vm{8x o
catch(Exception e) wu><a!3`=o
{ 4c95G^dZ
e.printStackTrace (); KO%$
} .@%L8_sMR
} 1G.?Y3DC<
09trFj$L
//日志 [z ]P5
public static void log(String sMsg) lS#:u-k
{ sW'_K.z
System.err.println(sMsg); x,]x>Up
} rMHh!)^#W
CLk,]kA'r
L\UGC%]9
public static void log(int sMsg) HfgTc h
{ ZSW@,Ti
System.err.println(sMsg); xr]bH.>
} 6W{Nw<
} n|6G\99l+M
\#LDX,=
rks"y&&Nc
/* s~2o<#
**TestMethod.java _z8"r&
*/ +])<}S!M
package NetFox; 8<mloM-4
H#D:'B j29
IN<nZ?D#
public class TestMethod { S{N4[U?V>
\8!CKnfs
2uN3:_w
public TestMethod() y6tqemz
{ ///xx/weblogic60b2_win.exe m$^5{qpg
try{ >r7PK45.K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fS/:OnH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O/FI>RT\H
SiteFileFetch fileFetch = new SiteFileFetch(bean); `h'l"3l
fileFetch.start(); `^[Tu 1
} /;+\6(+X
catch(Exception e){e.printStackTrace ();} pZopdEFDK|
gC(S(osF
}T(=tfv@
} iKV|~7nwO
;$zvm`|:
{l!{b1KJ
public static void main(String[] args) H`fJ<So?
{ ;22?-F^
new TestMethod(); hZ452W
} bRyxP2
} _b&26!gl
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