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)); 1^o})9
} qWK}
for(int i=0;i<nEndPos.length-1;i++) }2LG9B%
{ !Dc?9W!b
nEndPos = nStartPos[i+1]; vULDKJNHX
} GjEV]hqR
nEndPos[nEndPos.length-1] = nFileLength; &kdW(;`
} S".|j$
} XC6|<pru
pqs!kSJV
0*]0#2Z
//启动子线程 prO&"t >
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o]p$ w[5
for(int i=0;i<nStartPos.length;i++) o!h::j0,~
{ VB/75xK_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~uY5~Qs9G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U!+O+(
nStartPos,nEndPos,i); ]z7pa^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0o7o;eN
fileSplitterFetch.start(); >1Iw!SO+
} [i~@X2:Al
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nZj&Ma7R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pDP* 3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rk=w~IZJ3
nEndPos = " + nFileLength); OkQ< Sc
// fileSplitterFetch[nPos.length-1].start(); xs6!NY
M"c=_5P
&:d`Pik6
//等待子线程结束 KDg%sgRu}
//int count = 0; /FXb,)1t
//是否结束while循环 T^8`ji
boolean breakWhile = false; 68~]_r.a
1| WDbk
D {E,XOi
while(!bStop) Xl$r720ZJr
{ E\4ZUGy0
write_nPos(); uuHs)
Utility.sleep(500); rr1,Ijh{D
breakWhile = true; F'<XB~&o
7zQGuGo(
D@w&[IF
for(int i=0;i<nStartPos.length;i++) /FTP8XHwL)
{ (Ms #)E
if(!fileSplitterFetch.bDownOver) meB9:w[m
{ %j2:W\g:
breakWhile = false; }cW8B"_"
break; sn[<Lq
} QWm g#2'
} Rz>@G>b:
if(breakWhile) aAu%QRq
break; (8S+-k?
4nd)*0{f
>PWDo
//count++; :`yW^b
//if(count>4) !=vsY]
// siteStop(); KdlUa^}D
} %MtaWZ
!Y^B{bh
A@.ruG$
System.err.println("文件下载结束！"); }e"2Nc_UG
} IH=%%AS
catch(Exception e){e.printStackTrace ();} Jk<b#SZ[b
} v>hc\H1P
NCkrf]*F-
jRk1Iu|7
//获得文件长度 ywjD.od"v
public long getFileSize() B&3@b
{ >4lA+1JYk
int nFileLength = -1; ]C_$zbmi
try{ M1DV9~S
URL url = new URL(siteInfoBean.getSSiteURL()); 4GJx1O0Ol
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^7kYG7/
httpConnection.setRequestProperty("User-Agent","NetFox"); -k,}LJjo
D#ED?Lqf
PVq y\i
int responseCode=httpConnection.getResponseCode(); #R=6$
if(responseCode>=400) g>?,,y6/w
{ (=53WbOh/t
processErrorCode(responseCode); cpq0'x\
return -2; //-2 represent access is error ]x_14$rk
} %[?{H} y
Q`h@-6N
8 =3#S'n
String sHeader; [HRP&jr
Xs4G#QsAJ
r)w]~)8
for(int i=1;;i++) L~M6ca"
{ }WNgKw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]waCYrG<sY
//Utility.log(in.readLine()); <ot%>\C
sHeader=httpConnection.getHeaderFieldKey(i); :;3y^!
if(sHeader!=null) rYyEs I#qo
{ g3w-Le&T
if(sHeader.equals("Content-Length")) s\ ]Rgi>w
{ SP|Dz,o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V+y:!t`
break; wqn}t]
} wGpw+O
} y?s#pSX;N
else l0wvWv*k
break; f;W>:`'
} BjUz"69
} bJ.68643
catch(IOException e){e.printStackTrace ();} ps]s Tw
catch(Exception e){e.printStackTrace ();} ])T_&%
t7$2/C
0K^G>)l
Utility.log(nFileLength); 0c:jwtf
7[7Sm^Tw
WkY>--^
return nFileLength; ~F]If\b
} 0>?78QL9<
*j|BSd P
8:UV;5@
//保存下载信息（文件指针位置） SJI+$L\'
private void write_nPos() D)LqkfJ}z^
{ kKSn^qL*
try{ 852Bh'u_
output = new DataOutputStream(new FileOutputStream(tmpFile)); Qte'f+
output.writeInt(nStartPos.length); `ZAGseDd~
for(int i=0;i<nStartPos.length;i++) Kd,7x'h`E
{ BBm;QOBU
// output.writeLong(nPos); r \]iw v
output.writeLong(fileSplitterFetch.nStartPos); GfT`>M?QGK
output.writeLong(fileSplitterFetch.nEndPos); 6t6#<ts
} !Zf)N_k
output.close(); ,ffH:3F
} -Z%B9ql'
catch(IOException e){e.printStackTrace ();} 9/S-=VOe.t
catch(Exception e){e.printStackTrace ();} U_c9T>=
} s@bo df&
X5D}<J2"
H`ZUI8-
//读取保存的下载信息（文件指针位置） jJCd2O]
private void read_nPos() Q2/ZO2
{ E%C02sI
try{ T#sKld
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I_@XHhyVZ
int nCount = input.readInt(); iY1JU-S
nStartPos = new long[nCount]; s5ddGiZnBT
nEndPos = new long[nCount]; Cy##+u,C
for(int i=0;i<nStartPos.length;i++) $nbZ+~49
{ j"8|U E
nStartPos = input.readLong(); t.oP]_mI
nEndPos = input.readLong(); q6v%HF-q4
} w;Na9tR
input.close(); 2s@<k1EdPl
} ZMXIKN9BF#
catch(IOException e){e.printStackTrace ();} :Yqi5CR
catch(Exception e){e.printStackTrace ();} A#j'JA>_
} p1L8g[\
'PrrP3lO_~
{wx!~K
private void processErrorCode(int nErrorCode) /A;!g5Y
{ `!\`yI$!%w
System.err.println("Error Code : " + nErrorCode); BI-xo}KI
} @{!c [{x,T
'Nv*ePz
J@c)SK%2h
//停止文件下载 k:0HsN!F9
public void siteStop() \{[Gdj`
{ `8%2F}x}qD
bStop = true; ca1A9fvo
for(int i=0;i<nStartPos.length;i++) AA$-Lx(UJk
fileSplitterFetch.splitterStop(); dRXF5Ox5K}
u%vq<|~-
LCRZ<?O[|
} {?' DZR s
} 2!b+}+:
//负责部分文件的抓取 R1X{=ct
**FileSplitterFetch.java F+!K9(`|
*/ ,9W|$2=F
package NetFox; +,"/z\QO
n`krK"Ii
d&QB?yLd
import java.io.*; B6iH[dTy_
import java.net.*; @m[r0i0J"
-%lA=pS{Fq
'Bp7LtG92
public class FileSplitterFetch extends Thread { h$EH|9HAb
;V~[kF=t0
c_li.]P
String sURL; //File URL 0a??8?Q1G
long nStartPos; //File Snippet Start Position Q9b.]W
long nEndPos; //File Snippet End Position E1'HdOh&z
int nThreadID; //Thread's ID j ,'$i[F'
boolean bDownOver = false; //Downing is over 6WQT,@?
boolean bStop = false; //Stop identical c3&;Y0SD
FileAccessI fileAccessI = null; //File Access interface h7|#7 d
r9Wk7?w)
cf#2Wg)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !A )2<<4
{ 9""e*-;Mi
this.sURL = sURL; ? -PRS.=%
this.nStartPos = nStart; l* =\0
this.nEndPos = nEnd; i[_WO2
nThreadID = id; [kIiKLX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZzNp#FrX"
} x4PA~R
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Fcc\hV;
public void run() %o4ZD7@ '
{ Pwn3/+"%K
while(nStartPos < nEndPos && !bStop) \s8j*
{ |gW>D=rkj
0Z{f!MOh
J2M[aibV
try{ VFj}{Y
URL url = new URL(sURL); }]ak6'|[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W *t+!cU/:
httpConnection.setRequestProperty("User-Agent","NetFox"); [;`B
String sProperty = "bytes="+nStartPos+"-"; v&p|9C@
httpConnection.setRequestProperty("RANGE",sProperty); HrH-e=j
Utility.log(sProperty); 5J^S-K^r
;N4A9/)
Wp"+\{@)
InputStream input = httpConnection.getInputStream(); Z6eM~$Y
//logResponseHead(httpConnection); "&s9;_9
nCZ&FNi{O~
5G"DgG*<
byte[] b = new byte[1024]; u:Fa1 !4JR
int nRead; E)l0`83~^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iYi3x_A`
{ wJs#rkW
nStartPos += fileAccessI.write(b,0,nRead); 7{%_6b"
//if(nThreadID == 1) 8X,dVX5LT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !e5!8z
} PT7-_r
B8){
}&+b\RE
Utility.log("Thread " + nThreadID + " is over!"); uOzol~TU)
bDownOver = true; RjC3wO::
//nPos = fileAccessI.write (b,0,nRead); 'O%itCy)
} &DQyJJ`k
catch(Exception e){e.printStackTrace ();} .v?x>iV
} v803@9@
} WZ\bm$
A dNQS
^=f<WKn
//打印回应的头信息 WC6yQSnY&
public void logResponseHead(HttpURLConnection con) V(hM@ztN
{ F7!g+LPc<
for(int i=1;;i++) ,Jm2|WKH
{ &\8qN_`
String header=con.getHeaderFieldKey(i); ' U]\]Wp
if(header!=null) x3j)'`=15
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J:<mq5[
Utility.log(header+" : "+con.getHeaderField(header)); .E H&GX
else 3 q1LIM
break; 6'YT3=
} cR'l\iv+
} i2]7Bf)oV
1>I4=mj
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public void splitterStop() hk6(y?#
{ F|+Qi BO
bStop = true; '3BBTr%aZ
} vO>Fj
CD}::7$
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} 7s8-Uwl<
-|K^!G
<v&L90+s\;
/* H(L.k;B
**FileAccess.java dY=]ES}`
*//文件访问(定位，写) cQg:yoF
package NetFox; 5&59IA%S
import java.io.*; z$64Ep#
Y~E 8z
srzlr-J
public class FileAccessI implements Serializable{ SvTd#>ke
{5 V@O_*{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7+!FZo{?
RandomAccessFile oSavedFile; bVLBqa=
long nPos; _3Kow{y\
h^QLvOuR
pc/x&VY%
public FileAccessI() throws IOException p{@jM
{ -!@]z2uU
this("",0); ke2zxX2f
} .1{:Q1"S
ttP|}|O
|WkWZZ^
public FileAccessI(String sName,long nPos) throws IOException 1k)31GEQw
{ X%C`('"R
oSavedFile = new RandomAccessFile(sName,"rw"); *XUJv&ZN
this.nPos = nPos; 6o:b(v&Oo
oSavedFile.seek(nPos); v[Mh[CyB
} ltWEA
j.]ln}b/'+
XY`{F.2h
public synchronized int write(byte[] b,int nStart,int nLen) at|.Q*&a#
{ EpW89X
int n = -1; (Sv=R(_s
try{ p=XEMVqm
oSavedFile.write(b,nStart,nLen); "g5<jp
n = nLen; *w#^`yeo
} `w8Ejm?n
catch(IOException e) d[F3"b%
{ PIHix{YR
e.printStackTrace (); 49o/S2b4z
} ,Gi%D3lA
A3Xfu$[u
).32Im!;#R
return n; n-he|u
} Mdw"^x$7
NwcRH9};i
x%yzhIRR
} <YM!K8hu$
/B 53Z[yL
3,"G!0 y.
/* w-"tA`F4
**SiteInfoBean.java fKbg?
*/ eemC;JV%
package NetFox; rDWwu'
\4j(el
/g>]J70
public class SiteInfoBean { 84_Y+_9
=B{B?B"r
wii.0~p
private String sSiteURL; //Site's URL e +Ikw1y"f
private String sFilePath; //Saved File's Path 7\AoMk}
private String sFileName; //Saved File's Name R('\i/fy
private int nSplitter; //Count of Splited Downloading File 6{w'q&LYcE
Sa-" G`
N^{}Qvrr
public SiteInfoBean() Ou_2UT
{//nSplitter的缺省值为5 %0zp`'3Y
//default value of nSplitter is 5 F]L96&
this("","","",5); 12V-EG i
} \Ez&?yb/
*EPJeblAV
+V9(4la
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pwvmb\
{ %KPQ|^WE
sSiteURL= sURL; GMY[Gd
sFilePath = sPath; !<<wI'8
sFileName = sName; E&ReQgBft
this.nSplitter = nSpiltter; Us\Nmso z
?^ R"a##
9aYVbq""
} 50dx[v8
UJuz
iX6*OEl/Q
public String getSSiteURL() sVH w\_F$
{ l\TL=8u2c
return sSiteURL; U1D;O}z~
} d/b\:[B@
Z6nQW53-
ey$H2zmo
public void setSSiteURL(String value) hG}gKs
{ gX`C76P!
sSiteURL = value; }((P)\s
} (_Th4'(@Y
N+vsQ!Qz
dpT?*qLM
public String getSFilePath() )K]<\Q[
{ S rhBU6K
return sFilePath; }%c0EY'
} )1g\v8XT
Y}h&dAr
@cQ |`
public void setSFilePath(String value) T#KVN{O
{ HP=5a.
sFilePath = value; 8\+XtS
} (S_1C,
(rQ)0g@
9Qq%Fw_
public String getSFileName() D77$aCt
{ 16"L;r
return sFileName; aN';_tGvK
} t'DIKug&
\*#E4`Y
=%{E^z>1
public void setSFileName(String value) X=VaBy4#
{ G{.A5{
sFileName = value; \,G19o}`Es
} 5N907XVu
]_hXg*?
JY9hD;`6y
public int getNSplitter() 5IP@_GV|
{ n*hRlL
return nSplitter; ):V)Hrq?x
} CWkAc5
!H4uc
OQ _wsAA
public void setNSplitter(int nCount) _mDvRFq
{ 8u Z4[
nSplitter = nCount; h=_h,?_
} HqA3.<=F,
} r]%.,i7~8
}9?fb[]
EU()Nnm2
/* 6K5KkEp
**Utility.java w&}UgtEm
*/ LESF*rh=
package NetFox; cx4'rK.
3M{b:|3/q
_1?Fyu&<5
public class Utility { jqy?Od)
"#`c\JuR]
nb|"dK|
public Utility() z|G 39
{ |Vc:o_n7
~{s7(^ P
z(beT e
} eC-nV)]I9
q8vRUlf
//线程睡眠 rVx?Yo1F'
public static void sleep(int nSecond) :6Sb3w5h
{ FZtILlw
try{ ctL,Mqr\Z
Thread.sleep(nSecond); Jx= v6==7
} QX393v!
catch(Exception e) \JEI+A PY*
{ :#p!&Fi
e.printStackTrace (); VUGVIy.
} -%)8=
} AT,?dxP J
`'<&<P
//日志 [KjL`
public static void log(String sMsg) }[I|oV5*+&
{ =9vmRh?8
System.err.println(sMsg); REwZ41
} g3uI1]QXLg
jR&AQ-H&
})}-K7v1+
public static void log(int sMsg) sp$W=Wu7
{ :j0r~*z-
System.err.println(sMsg); nLjo3yvV..
} 9}6^5f?|
} [-Dl,P=
tmI2BBv
g:nU&-x#R
/* k"2xyzt*
**TestMethod.java SpUcrK;1
*/ :V#W y
package NetFox; A">A@`}
,M&[c|
MM%c
public class TestMethod { j/xL+Y(=
e RjpR?!\
-3T6ck
public TestMethod() *u%4]q
{ ///xx/weblogic60b2_win.exe =1"8ua
try{ L?n*b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U8(Rye$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hOSkxdi*^
SiteFileFetch fileFetch = new SiteFileFetch(bean); v+|N7
fileFetch.start(); h4^ a#%$
} ryq95<lF
catch(Exception e){e.printStackTrace ();} 'L2M W
{>cO&eiCt
Oj*3'?<7=
} ymBevL
dZ7+Iw;m
!s]LWCX+|
public static void main(String[] args) ZAPT5
{ r^k:$wJbRK
new TestMethod(); [a*m9F\ ,
} rnVh ]xJ
} RYaf{i`
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