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)); 8q_0,>w%
} 1/j$I~B
for(int i=0;i<nEndPos.length-1;i++) euRss#;
{ Z-Wfcnk
nEndPos = nStartPos[i+1]; :Am-8
} a4GWuozl
nEndPos[nEndPos.length-1] = nFileLength; dBEIMn@
} MB$a82bY
} a#(U2OP
vgPUIxB@
D(Ix!G/
//启动子线程 !c8L[/L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /J%do]PDl
for(int i=0;i<nStartPos.length;i++) 2YQ#-M
{ &{^eU5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XDmbm*~i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P[gO85
nStartPos,nEndPos,i); v+q<BYq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hYt7kq!"
fileSplitterFetch.start(); >S&U.
} wz#[:2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TL-i=\{L:d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }0eg{{g8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oj.lj!
nEndPos = " + nFileLength); )5l u.R%
// fileSplitterFetch[nPos.length-1].start(); ~@M7&%]
k&Jo"[i&WO
A!HK~yk~Q
//等待子线程结束 04-Zvp2
//int count = 0; 9`X&,S~e
//是否结束while循环 N=fz/CD)I
boolean breakWhile = false; ]6~k4
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while(!bStop) XL"=vbD
{ v&0d$@6/U
write_nPos(); |^5/(16
Utility.sleep(500); az(5o
breakWhile = true; i.@*tIK
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c cr" ep
for(int i=0;i<nStartPos.length;i++) 3"i%{
{ qpgU8f
if(!fileSplitterFetch.bDownOver) _Xh=&(/8@
{ sco uO$K
breakWhile = false; "Gh#`T0#a
break; )+GX<2_
} ,VG9)K1K
} zzJ^x8#R
if(breakWhile) f)gGH'yOQ
break; 6o lV+
*,jqE9:O
)1z4q`
//count++; O)<r>vqe}
//if(count>4) @ R'E?|
// siteStop(); ) hdgz$cl
} m!!;/e?yx
gE=Wcb!
&t[|%c*D&
System.err.println("文件下载结束！"); gHH&IzHF
} TNsg pJ?\
catch(Exception e){e.printStackTrace ();} vl~%o@*_
} HWbBChDF
GMb!Q0I8
W:B}u\)C
//获得文件长度 u[[/w&UV.,
public long getFileSize() (-2R{!A
{ !u0U5>ccw
int nFileLength = -1; .CmL7 5
try{ #_p
URL url = new URL(siteInfoBean.getSSiteURL()); oP-;y&AS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7K !GK
httpConnection.setRequestProperty("User-Agent","NetFox"); lm &^tjx
+3?`M<L0
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int responseCode=httpConnection.getResponseCode(); onh?/3l
if(responseCode>=400) 2mOfsn d@
{ AO8:|?3S
processErrorCode(responseCode); Tg\hx>
return -2; //-2 represent access is error P%jkKE?B4
} [Yoa"K
wz@/5c/u
+9~ZA3DiP
String sHeader; !h/dZ`#
% &+|==-
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for(int i=1;;i++) Sgx+V"bkT
{ e@+v9Bs]q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ei~]iZ}
//Utility.log(in.readLine()); yUj;4vd
sHeader=httpConnection.getHeaderFieldKey(i); y3AL)
if(sHeader!=null) :+1bg&wQ
{ 3Pa3f >}-
if(sHeader.equals("Content-Length")) ])68wqD
{ 9dw0<qw1%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?:JdRnH\
break; jqqaw
} jQ^Yj"6
} {Ot[WF
else KMe.i'
break; 5 2fO)!
} Nq U9/
} ndB@J*Imu
catch(IOException e){e.printStackTrace ();} S#hu2\9D,
catch(Exception e){e.printStackTrace ();} &}O8w77
SE-} XI\
{'&8`d
Utility.log(nFileLength); _32/WQF6
o:f|zf> i<
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return nFileLength; u4C1W|x
} <JJkki
l [x%I
&LwJ'h+nd
//保存下载信息（文件指针位置） P$F#,Cn
private void write_nPos() iF+S%aPd#
{ k~ZBJ+ 94
try{ dvxf lLd @
output = new DataOutputStream(new FileOutputStream(tmpFile)); p0?o<AA%O
output.writeInt(nStartPos.length); >Ziy1Dp
for(int i=0;i<nStartPos.length;i++) 6J]~A0vsi}
{ 89ZDOji?O
// output.writeLong(nPos); i"KL;t[1
output.writeLong(fileSplitterFetch.nStartPos); e ^-3etx
output.writeLong(fileSplitterFetch.nEndPos); ul}4p{ m[
} vN'VDvVM
output.close(); tvK rc
} J1& A,Gb
catch(IOException e){e.printStackTrace ();} kS[Dy$AB/2
catch(Exception e){e.printStackTrace ();} ;q'DGzh
} y K=S!7p\
C!`>cUhE{
c;nx59w]q
//读取保存的下载信息（文件指针位置） &boj$ k!g[
private void read_nPos() i<0D Z_rub
{ v5P*<U Ax
try{ /1H9z`qV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PlF89-
int nCount = input.readInt(); *C tsFS~
nStartPos = new long[nCount]; |:\$n}K
nEndPos = new long[nCount]; tc!!W9{69
for(int i=0;i<nStartPos.length;i++) 54;l*}8Hl
{ t.gq5Y.[
nStartPos = input.readLong(); Cbazwq
nEndPos = input.readLong(); eR(\s_`
} #IbS
input.close(); m`[oT\
} cYE./1D a
catch(IOException e){e.printStackTrace ();} C8!8u?k
catch(Exception e){e.printStackTrace ();} f&+XPd %
} k{zs578h2
7=; D0SS
0@JilGk1u
private void processErrorCode(int nErrorCode) q+r `e
{ ~r{\WZ.
System.err.println("Error Code : " + nErrorCode); J~M H_N
} G*8+h
C+ZQB)gn
'nC3:U
//停止文件下载 A!Knp=Gw
public void siteStop() TB;3`
{ >SY2LmV'a
bStop = true; hwEZj`9
for(int i=0;i<nStartPos.length;i++) 1kbT@
fileSplitterFetch.splitterStop(); f%`*ba"v
\Ac}R'
TW'E99wG
} e4[-rkn{hl
} {d&X/tT
//负责部分文件的抓取 )er?*^9Z
**FileSplitterFetch.java nNd`]F^U
*/ j;$6F/g
package NetFox; +9Xu"OFm
ey'pm\Z
OHx,*}N
import java.io.*; /&S~+~]n
import java.net.*; fho=<|-
} IIK~d,
|iLx$P6
public class FileSplitterFetch extends Thread { muK'h`
61ON
c+}!yH$
String sURL; //File URL R4z<Xf:!
long nStartPos; //File Snippet Start Position 94Kuy@0:+
long nEndPos; //File Snippet End Position Z%,\+tRe
int nThreadID; //Thread's ID 6\NX 5Gh
boolean bDownOver = false; //Downing is over JL}hOBqfI
boolean bStop = false; //Stop identical {mCKTyN+
FileAccessI fileAccessI = null; //File Access interface +#de8/x
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uW\@x4
{ GoGohsj
this.sURL = sURL; h(+m<J
this.nStartPos = nStart; ~`nm<
this.nEndPos = nEnd; =;'ope(?S
nThreadID = id; tdMP,0u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,yB?~
} xI.Orpw
4?P%M"\Iv
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public void run() i?1js! 8
{ 4Zv.[V]iOO
while(nStartPos < nEndPos && !bStop) kxr6sO~
{ =8$(i[;6w
^P3g9'WK
.(P@Bl]XJ
try{ .!7Fe)(x
URL url = new URL(sURL); $M}k%Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X]3l| D
httpConnection.setRequestProperty("User-Agent","NetFox"); =hZ&66
String sProperty = "bytes="+nStartPos+"-"; ft~|
httpConnection.setRequestProperty("RANGE",sProperty); al3BWRq'f
Utility.log(sProperty); +SZ%&
}"g21-T^
l`~a}y"n
InputStream input = httpConnection.getInputStream(); Z>>gXh<e[
//logResponseHead(httpConnection); ?9wFV/
!4qps$p{
p[af[!
byte[] b = new byte[1024]; $DABR
int nRead; q:EzKrE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !_^{udB}
{ v;N1'
nStartPos += fileAccessI.write(b,0,nRead); '0])7jq
//if(nThreadID == 1) Q5`+eQ?_\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eCPKpVhP
} !R] CmK
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lzr>WbM{{p
Utility.log("Thread " + nThreadID + " is over!"); :$GL.n-?
bDownOver = true; m-Z'K_oQ
//nPos = fileAccessI.write (b,0,nRead); c1)BGy li
} OTNZ!U/)j
catch(Exception e){e.printStackTrace ();} 9" }^SI8
} LoV*YSDAY
} ,\m;DR1
[+:mt</HN
3;t@KuQ66
//打印回应的头信息 ^cPo{xf
public void logResponseHead(HttpURLConnection con) F=*BvI"+
{ r+V(1<`2X
for(int i=1;;i++) ?}1JL6mF{
{ l?yZtZ8
String header=con.getHeaderFieldKey(i); EE{#S
if(header!=null) Mi%1+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mhJOR'2
Utility.log(header+" : "+con.getHeaderField(header)); k?|F0e_
else n8;G,[GM80
break; L8?Z!0D/h
} w/^0tZ~
} SS45<!iy
Fb\2df{@
sa0^1$(<
public void splitterStop() Rrs`h `'-
{ =JySY@?9
bStop = true; /RXk[m-
} om*tdG
]Nd'%M
tx|"v|&e2
} mAYr<=
X"qbB4(I
!5' 8a5
/* I")"s
**FileAccess.java -;/@;W
*//文件访问(定位，写) kw-Kx4 )
package NetFox; ]~g|SqPA@
import java.io.*; =aCIaL&9Y
9bzYADLI
+hKPOFa'
public class FileAccessI implements Serializable{ L2/<+Zw
[r~rIb%Zj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \3y=0
RandomAccessFile oSavedFile; #`6OC)1J
long nPos; HS5Ug'\446
WKYA9BaR
|+4E 8;4_
public FileAccessI() throws IOException 31o7R &v
{ [}xIg8
this("",0); 9>$%F;JP44
} |qudJucV
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public FileAccessI(String sName,long nPos) throws IOException 6!}m$Dvt~
{ A0N ;VYv
oSavedFile = new RandomAccessFile(sName,"rw"); ~_l:b
this.nPos = nPos; BGh8\2
oSavedFile.seek(nPos); WX[dM }L
} 1WA""yb
)>#<S0>'j
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public synchronized int write(byte[] b,int nStart,int nLen) r^o}Y
{ \Dsl7s=
int n = -1; i]^*J1a
try{ :R|2z`b!
oSavedFile.write(b,nStart,nLen); r<f-v_bxF
n = nLen; I+4qu|0lA
} *i]Z=
catch(IOException e) E/ed0'|m
{ XGrxzO|{
e.printStackTrace (); Z]>e& N
} \8>N<B)
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hwol7B>
return n; ?[>BssW
} :#!F 7u
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*}WqYqOow
} ?$8 ,j+&I
K?9H.#(
$m%/veD k
/* G}hkr
**SiteInfoBean.java B8#f^}8
*/ "F.J>QBd
package NetFox; O9 Au =
;uo|4?E:\(
$}h_EI6hS
public class SiteInfoBean { qpEC!~y
8'_ ]gfF
$MVeMgPa
private String sSiteURL; //Site's URL W!9f'Yn
private String sFilePath; //Saved File's Path RV@(&eM
private String sFileName; //Saved File's Name D]>86&
private int nSplitter; //Count of Splited Downloading File T6?d`i i1
93p9?4;n-
RkXLE"G'
public SiteInfoBean() 'w$we6f
{//nSplitter的缺省值为5 +z/73s0~
//default value of nSplitter is 5 HBkQ`T
this("","","",5); *q9$SDm
} )da8Ru
!m.')\4<
).#D:eO[~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %;XuA*e
{ ;og<eK
sSiteURL= sURL; n#AH@`&i
sFilePath = sPath; / z>8XM&
sFileName = sName; rO>wX_
this.nSplitter = nSpiltter; |`9zE]
a{YVz\?d}
I)4|?tb?
} p.7p,CyB
RPqn#B
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public String getSSiteURL() @[N~;>
{ -Y,Ibq
return sSiteURL; 4'eVFu+62
} 9 u89P
k5\ zGsol
@ShJ:
public void setSSiteURL(String value) j{+I~|ZB,
{ H;}ue
sSiteURL = value; C2%3+
} *m Tc4&*
Xpz-@fqKdf
.TU15AAc
public String getSFilePath() @?NLME
{ NNV.x7
return sFilePath; 24k}~"We
} p+1B6j
N9hWx()v
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public void setSFilePath(String value) g}`CdVQ2M<
{ R1%T>2"~&
sFilePath = value; !f[N&se
} 3JO:n6
\DdVMn
?4dd|n
public String getSFileName() &%51jM<
{ A)0m~+?{J
return sFileName; G`K7P`m
} KUV{]?'
,tc]E45
obkv ]~
public void setSFileName(String value) a'.=.eDQ
{ }{PtQc6RL!
sFileName = value; ~oyPmIcb
} W| eG}`
Hd}t=6
^8t*WphZC
public int getNSplitter() K_Gf\x
{ @y%qQe/g
return nSplitter; Gs?sO?j
} Xc<9[@
Cf 8-%
{i?K~| h
public void setNSplitter(int nCount) a.Vs>1
{ ITOGD
nSplitter = nCount; P=i |{vv(
} l)eaIOyk
} 2Nszxvq,
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xpo}YF'5
/* v<4X;4p^
**Utility.java jtJU5Q
*/ O~1p]j
package NetFox; FiH!)6T
S!c@6&XJm?
@uWD>(D
public class Utility { U;Wmx
7E]l=Z`x
p#I1l2nE
public Utility() }e6:&`a xD
{ 3@A k6Uh
s;)tLJ!
;<Q_4 V
} @J)vuGS
7tnzgtal
//线程睡眠 `fHiY.-
public static void sleep(int nSecond) :"^$7
{ HuClO
try{ Y`RfE
Thread.sleep(nSecond); F:U_gW?
} Gj0NN:
catch(Exception e) cZ,_O~
{ z[Qv}pv
e.printStackTrace (); Z/;SR""wa
} O`| ri5d
} Q?q m~wD
m]vr|:{6/
//日志 Sy~Mh]{E
public static void log(String sMsg) IT"jtV
{ {hR23eE)#
System.err.println(sMsg); \/GY0s
} HyMb-Us
sJvn#cS
`_ L|Is=n
public static void log(int sMsg) 7u(i4O& k
{ &ICO{#v5
System.err.println(sMsg); lDXH<W?
} 8hY)r~!b'
} G 0 yt%qHE
q5Mif\
1jb@nxRjO
/* f#+ h_1#
**TestMethod.java /+7L`KPD
*/ _69\#YvCG
package NetFox; ivk|-C'\
=Ch#pLmH
YWdvL3Bgk,
public class TestMethod { _X/`4 G
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:4TcCWG
public TestMethod() t~M_NEPxV
{ ///xx/weblogic60b2_win.exe $P~a
try{ NI)nf;C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W525:h52{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wov_jVdN\
SiteFileFetch fileFetch = new SiteFileFetch(bean); +d96Z^KUhv
fileFetch.start(); cm<3'#~Q?
} b"V-!.02
catch(Exception e){e.printStackTrace ();} dWSH\wm+
.BvV[`P
IU}`5+:m
} :|TBsd|/x
$+j)
a{=~#u8
public static void main(String[] args) 6]*qx5m`<l
{ }"v"^5
new TestMethod(); >XN&QVE
} j3U8@tuG
} x$*OglaS
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