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)); <|!?V"`3
} pk%%}tP<
for(int i=0;i<nEndPos.length-1;i++) [tKH'}/s=
{ #-]!;sY>
nEndPos = nStartPos[i+1]; :>:F6Db"U
} FZt a
nEndPos[nEndPos.length-1] = nFileLength; v%ldg833l
} N;YAG#'9~_
} eK=W'cNu
Y#VtZTcT
eWN[EJI<
//启动子线程 GOKca%DT=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X j>?P/=Z
for(int i=0;i<nStartPos.length;i++) ! sN~w
{ >@Nn_d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m-<"`:+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X,]E {
nStartPos,nEndPos,i); LU-,B?1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c:J;Q){Xz
fileSplitterFetch.start(); '`)r<lYN,
} T J!d7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A~@u#]]<n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (~6D`g`B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W~!uSrY
nEndPos = " + nFileLength); U,tl)(!@Q-
// fileSplitterFetch[nPos.length-1].start(); W Ai91K@
O`;e^PhN
[Yq*DkW
//等待子线程结束 Y"n$d0%
//int count = 0; 1edeV48{:
//是否结束while循环 j3Sz+kOf,
boolean breakWhile = false; 0SHF 8kek
z]twh&^1L
j>}<FW-N
while(!bStop) 6h5,XcO4
{ 0b)q,]l]
write_nPos(); 5DI&pR1eZ
Utility.sleep(500); <>Nq]WqA
breakWhile = true; >" &&,~
mRECdGst
`W*b?e|H1
for(int i=0;i<nStartPos.length;i++) NwISf
{ i$z).S?1
if(!fileSplitterFetch.bDownOver) hhM?I$t:
{ /c&;WlE/n
breakWhile = false; r(VGdG
break; |z+K]R8_
} sTb@nrRxH
} oEuV&m|yX
if(breakWhile) :L6,=#
break; j><8V Qx
b9%G"?~Zz
X!AD]sK
//count++; DNyU]+\L[l
//if(count>4) >Oz~j>jL
// siteStop(); ?BEO(;'
} xoYaL
U WU PY
>.76<fni
System.err.println("文件下载结束！"); smJ#.I6/L
} eyIbjgpV
catch(Exception e){e.printStackTrace ();} dfa^5`_
} sN8)p%'Lg
>T)#KQ1t
*#| lhf'
//获得文件长度 VGVb3@
public long getFileSize() ImG7E w
{ :~ ; 48m
int nFileLength = -1; u&npUw^Va
try{ ,K-?M5(n9
URL url = new URL(siteInfoBean.getSSiteURL()); B7u4e8(E*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S_|VlI
httpConnection.setRequestProperty("User-Agent","NetFox"); g{U?Y"
1M<;}hJ{/
B=;pwX
int responseCode=httpConnection.getResponseCode(); )_H>d<di
if(responseCode>=400) -Z<V?SFOK
{ VmbfwHRWb
processErrorCode(responseCode); "Ei' FM
return -2; //-2 represent access is error $psPNJG
} j +u3VP
O,Sqh$6U
}%lk$g';
String sHeader; !hc#il'g].
l(j._j~p
}^"#&w3<
for(int i=1;;i++) j3$\+<m]
{ !gX(Vh*k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bH1MDBb2
//Utility.log(in.readLine()); -S6^D/(;
sHeader=httpConnection.getHeaderFieldKey(i); }Lc8tj<
if(sHeader!=null) ZBxV&.9/
{ xC^|S0B
if(sHeader.equals("Content-Length")) e{k)]]J
{ BqG7Et
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C?-_8OA
break; V=-hqo(
} .cCB,re
} tFrNnbmlQ
else \O G`+"|L
break; *{1]b_<
} i^_?C5
} .'Rz tBv
catch(IOException e){e.printStackTrace ();} v_L?n7c
catch(Exception e){e.printStackTrace ();} 'ngx\Lr
7a5G,C#QQ
UkzLUok]U
Utility.log(nFileLength); .J fV4!=o
(|t)MnPfY
<HMmsw
return nFileLength; I5H#]U
} E7AYK&
-s,guW |
&O;'?/4 S
//保存下载信息（文件指针位置） %YV3-W8S0
private void write_nPos() m14OPZ<3?-
{ %5-
try{ M?G4k]
output = new DataOutputStream(new FileOutputStream(tmpFile)); -xMM}r y
output.writeInt(nStartPos.length); @mRda%qR
for(int i=0;i<nStartPos.length;i++) v#ERXIrf
{ I?#B_R#
// output.writeLong(nPos); GGF;4
output.writeLong(fileSplitterFetch.nStartPos); "Wz74ble
output.writeLong(fileSplitterFetch.nEndPos); FtmI\,
} H;kk:s'
output.close(); @(I)]Ca%O
} #1VejeTi
catch(IOException e){e.printStackTrace ();} y>iote~
catch(Exception e){e.printStackTrace ();} k`;&??
} _ H$^m#h
y1*z,"dx
GkYD:o=qx
//读取保存的下载信息（文件指针位置） `bMwt?[*
private void read_nPos() S/H!a:_5r
{ 3lo.YLP^
try{ .p?kAf`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )uxXG`,h
int nCount = input.readInt(); 8Ssk>M*
nStartPos = new long[nCount]; @$] CC1Y
nEndPos = new long[nCount]; r}~|,O3bc'
for(int i=0;i<nStartPos.length;i++) "Qfw)!#
{ ]~J.YX9ST
nStartPos = input.readLong(); Qu6Q)dZ<
nEndPos = input.readLong(); ganXO5T$
} !PuW6
input.close(); \r^*4P,,
} C$#X6Q!,
catch(IOException e){e.printStackTrace ();} [>xGynU0
catch(Exception e){e.printStackTrace ();} 8^)K|+_'m
} O}cg1Q8p
y jQpdO
:^*9Eb
private void processErrorCode(int nErrorCode) M-+pYv#&P
{ n=tg{_9f%
System.err.println("Error Code : " + nErrorCode); <'l;j"&lp
} (14J~MDB
-Ka0B={Z
dd|/I1
//停止文件下载 Mg^.~8\de
public void siteStop() .BqSE
{ &Dw8GU}1
bStop = true; ?~fuMy B
for(int i=0;i<nStartPos.length;i++) hY^-kdQ>M
fileSplitterFetch.splitterStop(); {nyVC%@Y
/m+q!yi &
E])X$:P?
} WTZr{)e
} }2i3
//负责部分文件的抓取 N,Ys}qP
**FileSplitterFetch.java "H!2{l{
*/ =`y.L5
package NetFox; *3r{s'm
8jxs%N,aI
PN@[k:5(
import java.io.*; gt= _;KZ
import java.net.*; fsVQZ$h73
^7O,Vk"Z
G: p!PB>=
public class FileSplitterFetch extends Thread { ' *x?8-KP
FMBzTD
M+q|z0U
String sURL; //File URL ~.'NG? %7P
long nStartPos; //File Snippet Start Position 1XvB,DhJ
long nEndPos; //File Snippet End Position ]&kzIxh
int nThreadID; //Thread's ID _m8JU
boolean bDownOver = false; //Downing is over 5qW*/
boolean bStop = false; //Stop identical TRSR5D[
FileAccessI fileAccessI = null; //File Access interface c7$U0JO
)/1,Ogb%_
Z-BPC|e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;q6FdS
{ B\z4o\am%
this.sURL = sURL; #H1ng<QV
this.nStartPos = nStart; E%E3h1Ua
this.nEndPos = nEnd; g,seqh%
nThreadID = id; j)[ wX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R9B!F{! 5
} 3"OD"
B U^3Ux$
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public void run() u teI[Q
{ (&x#VmDL
while(nStartPos < nEndPos && !bStop) K[(h2&
{ &v#*
#[a+m
8`/nk`;
try{ (!^(74
URL url = new URL(sURL); o]vU(j_Ju
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (8*& 42W
httpConnection.setRequestProperty("User-Agent","NetFox"); Y"U -Rc
String sProperty = "bytes="+nStartPos+"-"; i C nWb
httpConnection.setRequestProperty("RANGE",sProperty); k_c8\::p#
Utility.log(sProperty); 2Hp#~cE+.
c%+9uu3
fy`e)?46
InputStream input = httpConnection.getInputStream(); ,.ln
//logResponseHead(httpConnection); Y:0SrB!\
z7H[\4A!>
O)tZ`X;
byte[] b = new byte[1024]; TCd1JF0
int nRead; N?'V,p 0=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M8,W|eTM
{ Z ?{;|Z5
nStartPos += fileAccessI.write(b,0,nRead); b%fn1Ag9
//if(nThreadID == 1) aiKZ$KLC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mt+IB4`
} 0O,l rF0'
4ZK8Y[]Lv
54Baz
Utility.log("Thread " + nThreadID + " is over!"); xM/B"SG2
bDownOver = true; i7fQj, q
//nPos = fileAccessI.write (b,0,nRead); [V5ebj:6w
} Bk~lE]Q3c7
catch(Exception e){e.printStackTrace ();} ,\|W,N}~
} 9W{=6D86e
} }lk_Oe1
EEaf/D/jt
2B# ]z
//打印回应的头信息 ,4-) e
public void logResponseHead(HttpURLConnection con) )k.[Ve
{ 'wd-!aZAd
for(int i=1;;i++) SY` U]-h
{ IQS:tL/
String header=con.getHeaderFieldKey(i); T>&d/$;]
if(header!=null) wnL\.%Y^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _d'x6$Jg
Utility.log(header+" : "+con.getHeaderField(header)); 24)3^1P\V
else gUlZcb
break; >FO=ioNY
} A,@"(3
} r\?*?sL
M_DkjuR
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public void splitterStop() Q&7Qht:ea:
{ pw .(6"
bStop = true; QaV*}W
} ~V4|DN[I
[aW#7
-!"8j"pA:
} <KCgtO
e5Z\v0
=W?c1EPLCx
/* ;#*mB`
**FileAccess.java 7Uh}|6PU
*//文件访问(定位，写) i "xq SLf=
package NetFox; O`4X[r1LD
import java.io.*; 6gn|WO=Wf
mvnK)R_
l"64w>,
public class FileAccessI implements Serializable{ +4 dHaj6
e3.TGv7=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .,4&/cd
RandomAccessFile oSavedFile; xxYFWvi
long nPos; (s*}=
QLn5:&
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public FileAccessI() throws IOException Sq,x@
{ .%o:kq@B
this("",0); NGxuwHIQ8
} 8LOzL,Ah
x!J L9
&,+ZNA`P
public FileAccessI(String sName,long nPos) throws IOException )+J?(&6
{ | e+m!G1G
oSavedFile = new RandomAccessFile(sName,"rw"); 15B$Sp!/`e
this.nPos = nPos; ZD*>i=S
oSavedFile.seek(nPos); g`6S*&8I
} Gl+}]Vn[n
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,QDq+93
public synchronized int write(byte[] b,int nStart,int nLen) }-!$KR]:s
{ m&2m' =(
int n = -1; }w$/x<Q[
try{ jhHb[je~{4
oSavedFile.write(b,nStart,nLen); *GA#.$n
n = nLen; `7NgQ*g.d/
} Z`[j;=[
catch(IOException e) 0xsvxH"*
{ 3x#G SS
e.printStackTrace (); >Kxl+F
} mJ-@:5
oR~+s&c
jRGG5w}
return n; yy9Bd>
} SL(Q;_
u931^~Ci
i''dY!2
} 0]T ;{
iS{)Tll}&
1oC/W?l^
/* 0-QkRr_I
**SiteInfoBean.java Z|)~2[Roa
*/ b{sFN!
package NetFox; wM><DrQ
=w8*n2
>k:)'*
public class SiteInfoBean { ,5q^/h
t ;[Me0
t.m $|M>
private String sSiteURL; //Site's URL ivt\| >
private String sFilePath; //Saved File's Path !-: a`Vs+
private String sFileName; //Saved File's Name 2)G ZU
private int nSplitter; //Count of Splited Downloading File X;-,3dy
a].Bn#AH!C
]UMwpL&rY
public SiteInfoBean() ;$Wa=wHb
{//nSplitter的缺省值为5 #GTmC|[
//default value of nSplitter is 5 r/PsFv{8
this("","","",5); 3#dUQ1qo6
} 'oo]oeJ-
Cu>pql<O
k(Ow.nkb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -WEiY
{ 7"M7N^
sSiteURL= sURL; l_DPlY
sFilePath = sPath; %e_WO,R
sFileName = sName; U9Y'eP.2
this.nSplitter = nSpiltter; u+{5c5_
rGoB&% pc
L/V3sSt
} EQg 6*V
o#;w>-
1W5YS +pf
public String getSSiteURL() cZ5[A T
{ 2t_E\W7w+
return sSiteURL; MEg|AhP
} 9~a_^m/
y#r=^r]l)
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public void setSSiteURL(String value) lnTl"9F
{ aFKks .n3
sSiteURL = value; Il!iqDHz3
} hd+JKh!u
F/mD05{
8amtTM
public String getSFilePath() 594$X@!v
{ \,~gA
return sFilePath; 0\u_\%[
} WpRi+NC}ln
CKj3-rcF(
|`#[jHd
public void setSFilePath(String value) Ie``Wb=
{ (Iu5QLE
sFilePath = value; =$fxK
} O>H4hp
\}Hk`n)Aq
b@nbXm]Z
public String getSFileName() S&@~F|
{ 6jom6/F 4
return sFileName; B,}%1+*
} {?,:M
9'O<d/xj/
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public void setSFileName(String value) AlGD .K
{ ,v(G2`Z
sFileName = value; GMd81@7
} #~nI^ ggW
vrh}X[JEw'
<PXA`]x~
public int getNSplitter() |qfnbi-\
{ D`iWf3a.
return nSplitter; L[<MBgFKv
} SrU,-mA W
L[rJ7:
*j8w" 4
public void setNSplitter(int nCount) &:w{[H$-
{ :'#BU:
nSplitter = nCount; hnL(~
} %kKtPrT
} jUdW o}/
HH8a"Hq)
_/7[=e}y
/* tlG&PVvr
**Utility.java ;v#~o*
*/ fH}`
package NetFox; m&b!\"0
Ws}u4t
8ec~"vGLz~
public class Utility { 7J##IH+z35
Oxy.V+R
"!r7t4
public Utility() BB=%tz`B
{ cYW F)WAog
;<MHDmD
[BmondOx
} `ffWV;P
IB(5 &u.
//线程睡眠 N(/DC)DJg
public static void sleep(int nSecond) V<P@hAAr
{ ZJ u\
try{ 8%I4jL<
Thread.sleep(nSecond); 7S),:Uy[\
} RVX-3FvP
catch(Exception e) ;w[|IRa
{ :@19,.L
e.printStackTrace (); '0z@Jevd?
} GXJJOy1"!
} ln#Lx&r;|
A.*}<
//日志 TE^BfAw@
public static void log(String sMsg) Uo5l =\
{ cD]{ Nn
System.err.println(sMsg); L@9"6&
} bZ:w_z[3=
ZN',=&;n'
5H`k$[3V
public static void log(int sMsg) ?ZE1>L7e
{ 8BC}D+q
System.err.println(sMsg); !Vv$
} ^=FtF9v
} ?,TON5Fl-
jats)!:
9Jaek_A`
/* Z3T:R"l;
**TestMethod.java |Zncr9b
*/ !$f@j6.
package NetFox; )#M*@e$k
Ga"$_DyM
5}E8Tl
public class TestMethod { kMf]~EZ?
2Pasmh
?RA^Y N*9
public TestMethod() Azq,N@HO
{ ///xx/weblogic60b2_win.exe ;Rt?&&W
try{ Skq%S`1%Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d*7 Tjs{\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b:WlB[5
SiteFileFetch fileFetch = new SiteFileFetch(bean); rW&8#&
fileFetch.start(); bxK1v7
} &=xm>;`3
catch(Exception e){e.printStackTrace ();} cdf8YN0!
=0MW+-
/0\m;&
} {{SeD:hx
l%rwJLN1
/t(dhz&xN
public static void main(String[] args) X+ h|sy
{ #=q)>+\
new TestMethod(); "#qyX[\
} Ks{^R`Oau
} B}C"Xc
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