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)); PO]c&}/
} o/I`L
for(int i=0;i<nEndPos.length-1;i++) *|3G"B{w6
{ w(!COu
nEndPos = nStartPos[i+1]; *o#P)H
} [^\HP]*Q{
nEndPos[nEndPos.length-1] = nFileLength; _4X3g%nXl
} I8
} !u=A9i!
ac/<N%
4+B OS ~
//启动子线程 ^ZDpG2(zk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QlH,-]N$L
for(int i=0;i<nStartPos.length;i++) <U2Un 0T
{ 3t:/Guyom8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &h;J_Ps
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b("M8}o
nStartPos,nEndPos,i); 7\EY&KI"0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ifcC [.im
fileSplitterFetch.start(); m4'x>Z
} #PA 9bM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7;Vqr$9)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 80Z'1'u0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rLI);!^-
nEndPos = " + nFileLength); }+GIrEDId
// fileSplitterFetch[nPos.length-1].start(); n]v,cfn/=<
*ZV=4[#bT
+o}mV.&1,
//等待子线程结束 ]Jx_bs~g
//int count = 0; e<HHgC#J
//是否结束while循环 o@DlK`
boolean breakWhile = false; 5<h:kZ"S^g
]E}eM@xdD
}\hz@G<
while(!bStop) p JM&R<i:
{ `(lD]o{,s
write_nPos(); fzW!-
Utility.sleep(500); 9wpV} .(
breakWhile = true; U$wD'v3pw
t}f,j^`e
~cb7]^#u1l
for(int i=0;i<nStartPos.length;i++) "\l#q$1h
{ asKAHVT(
if(!fileSplitterFetch.bDownOver) nlR7V.
{ NrWgaPO)i
breakWhile = false; =4:]V\o):'
break; Q<2`ek
} ZoT8
} s=83a{#K
if(breakWhile) )wfqGkr=m!
break; C0 o
2~)r,.,
%%hG],w
//count++; ]seOc],4
//if(count>4) ?j@(1",=&
// siteStop(); R9)"%SO<y
} \'-E[xNcWI
V8"m_
5PPaR|c3
System.err.println("文件下载结束！"); e&ci\x%
} ^#)]ICV
catch(Exception e){e.printStackTrace ();} tQmuok4"d
} 7s}Eq~
GfL:0
.[C@p`DZ
//获得文件长度 ,]_<8@R
public long getFileSize() p\ _&
{ T!Z).PA#
int nFileLength = -1; o'Kl+gw4
try{ 0c$ ')`!m
URL url = new URL(siteInfoBean.getSSiteURL()); 8;"HM5+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YzeNr*
httpConnection.setRequestProperty("User-Agent","NetFox"); ID8u&:
U\x$@J
6QG"~>v7'(
int responseCode=httpConnection.getResponseCode(); 4-JyK%m,0
if(responseCode>=400) W9/HM!
{ !]t5(g_
processErrorCode(responseCode); `xF^9;5mi
return -2; //-2 represent access is error =.ReM_.
} X}_Gk5q*
Y [%<s/
TWSx9ii!M:
String sHeader; y4j\y ? T8
]jgMN7
9oTtH7%
for(int i=1;;i++) 7)dCdO
{ b;IzK'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J)._&O$
//Utility.log(in.readLine()); 0Q!/A5z
sHeader=httpConnection.getHeaderFieldKey(i); uXo?
if(sHeader!=null) x<\5Jrqt
{ Df.eb|[{
if(sHeader.equals("Content-Length")) OZ6:u^OS]
{ xt1Ug~5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .njk^,N
break; H_>9'(
} |}isSCt
} %abc-q
else v?(z4oOD/>
break; Ff&kK5}q
} >.&E-1[+:
} XNQPyZ2@|b
catch(IOException e){e.printStackTrace ();} /|>?!;
catch(Exception e){e.printStackTrace ();} 6d/1PGB
IH3Nkpsg
O 4'/C]B2
Utility.log(nFileLength); ky@ZEp=
=[nuesP'
8'#L+$O &N
return nFileLength; ErxvGB(2
} EHk$,bM
_@OS,A
y_LFkZ
//保存下载信息（文件指针位置） AwWo,Y399h
private void write_nPos() |./{,",
{ ;.Y-e Q,
try{ @wcrtf~{)&
output = new DataOutputStream(new FileOutputStream(tmpFile)); .,<w_=
output.writeInt(nStartPos.length); q0L\{
for(int i=0;i<nStartPos.length;i++) *>E_lWW.
{ {h0T_8L/
// output.writeLong(nPos); d9q`IZqee
output.writeLong(fileSplitterFetch.nStartPos); !nL>Ly
output.writeLong(fileSplitterFetch.nEndPos); KpC!C9
} Of m0{c=
output.close(); /p$+oA+
} TGHyBPJb
catch(IOException e){e.printStackTrace ();} Af Y]i
catch(Exception e){e.printStackTrace ();} U3~rtc*
} y 'Ah*h
A$70!5*
bMB*9<c~
//读取保存的下载信息（文件指针位置） <RuLIu
private void read_nPos() {'sp8:$a
{ %\T#Ik~3
try{ m\G45%m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *R3^:Y&
int nCount = input.readInt(); <b-OdOg
nStartPos = new long[nCount]; |cgc^S/~H
nEndPos = new long[nCount]; {$Z S 27
for(int i=0;i<nStartPos.length;i++) Tly*i"[&
{ SvQ!n4 $
nStartPos = input.readLong(); *yYeqm
nEndPos = input.readLong(); 8(g}/%1mt3
} p# JPLCs
input.close(); _6-N+FI
} HT7I~]W
catch(IOException e){e.printStackTrace ();} -f["1-A
catch(Exception e){e.printStackTrace ();} )zkr[;j~`
} r-o+NV
B*:W`}G]_c
?-JW2 E"uT
private void processErrorCode(int nErrorCode) Q7-'5s
{ OmlM9cXm^4
System.err.println("Error Code : " + nErrorCode); BvP++,a&Sa
} -?w3j9kk>
|f1RhB
i?861Hu
//停止文件下载 Ffig0K+`
public void siteStop() (L`IL e*
{ UJ><B"
bStop = true; o:`^1
for(int i=0;i<nStartPos.length;i++) `=%G&_3_<
fileSplitterFetch.splitterStop(); PLq]\y
o)+C4f[G4
AnoA5H
} |h& q
} Ml6}47n
//负责部分文件的抓取 'EC0|IT)c
**FileSplitterFetch.java a fLE9
*/ M[cAfu
package NetFox; qtuT%?wT@Z
}=A+W2D
39A|6>-?
import java.io.*; =R*IOJ
import java.net.*; p-*{x
=^z*p9ZB
A3|2;4t
public class FileSplitterFetch extends Thread { mbHMy[R
9Zr6 KA{
;H9 W:_ahE
String sURL; //File URL |XmzqX%
long nStartPos; //File Snippet Start Position -Gjz+cRns
long nEndPos; //File Snippet End Position 4kR;K!@k
int nThreadID; //Thread's ID GJ:oUi
boolean bDownOver = false; //Downing is over 2V*;=cv~z
boolean bStop = false; //Stop identical MAQ-'s@
FileAccessI fileAccessI = null; //File Access interface Y$_^f*sFn
,(f({l[J}
'p)DJUwt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~5>TMIDiuR
{ bnN&E?{hF1
this.sURL = sURL; W9]0X
this.nStartPos = nStart; *0m|`- T
this.nEndPos = nEnd; {vk%&{D0)
nThreadID = id; &%tW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <) -]'@*c
} -`$J& YU
58R.`5B
(:R5"|]@<x
public void run() y5XFJj
{ #mD_<@@
while(nStartPos < nEndPos && !bStop) ?rziKT5OOC
{ }{mS"
%vbov}R
_+Z5qUmQ
try{ fKO@Qx]
URL url = new URL(sURL); KN&|&51p}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >1HXC2 Y
httpConnection.setRequestProperty("User-Agent","NetFox"); ^S 45!mSb
String sProperty = "bytes="+nStartPos+"-"; n8JM 0 U-
httpConnection.setRequestProperty("RANGE",sProperty); aSI%!Vg.
Utility.log(sProperty); i=&]%T6Qk
)1 QOA
9A87vs4[
InputStream input = httpConnection.getInputStream(); /S@iF
//logResponseHead(httpConnection); R G~GVf
di7cCn
kOC0d,
byte[] b = new byte[1024]; -j1]H"-
int nRead; *?A!`JpJn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nZM]EWn
{ u95D0S
nStartPos += fileAccessI.write(b,0,nRead); qpzyl~g:C
//if(nThreadID == 1) dF5y' R'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |io)?`pj
} -Rx;"J.H
^}`24~|y
B~b ='jN
Utility.log("Thread " + nThreadID + " is over!"); uMRzUK`QK
bDownOver = true; 40z1Qkmaey
//nPos = fileAccessI.write (b,0,nRead); yCkX+{ki
} P6({wx
catch(Exception e){e.printStackTrace ();} 7~;)N$d\
} xrI9t?QaCb
} d%K{JkD-
ca5;Z@t$S
`i+2YCk
//打印回应的头信息 )`6OSB
public void logResponseHead(HttpURLConnection con) [.6bxK
{ B ]sVlbt
for(int i=1;;i++) M.bkFuh
{ vP\6=71Y
String header=con.getHeaderFieldKey(i); / %iS\R%ca
if(header!=null) Z~[eG"6zI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4~8-^^
Utility.log(header+" : "+con.getHeaderField(header)); TX7dwmt)N
else sHPj_d#
break; "<f?.l\+
} L(9AcP
} (*,R21<%
e_g&L)
BqDsf5}jpA
public void splitterStop() JB=L{P J
{ 43<i3O
bStop = true; 8k+k\V{
} @Kw&XKe`
b `bg`}x
JY,oXA6O
} -BWWaL
[k&7h,
w,_LC)9
/* O[z6W.
**FileAccess.java }:QoYNq
*//文件访问(定位，写) N vTp1kI]
package NetFox; G:`So
import java.io.*; KC%&or
CrG!8}
&}K%F)S
public class FileAccessI implements Serializable{ UMT}2d%
B\l0kiNT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |;^$IZSsz
RandomAccessFile oSavedFile; lR mVeq:
long nPos; [nlq(DGJhp
K<%8.mZ7
p["pGsf
public FileAccessI() throws IOException fI'+4 )@x
{ :nfy=*M#
this("",0); rq\<zx]au
} UUa@7|x
K$B~vy6E`
66$hdT$
public FileAccessI(String sName,long nPos) throws IOException DZA '0-
{ 'pO-h,{TS
oSavedFile = new RandomAccessFile(sName,"rw"); [fELf(;(
this.nPos = nPos; b!teSf
oSavedFile.seek(nPos); .[1@wW&L
} *P&lAyt6
g>`D!n::n
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public synchronized int write(byte[] b,int nStart,int nLen) .9Dncsnf,`
{ N9M",(WTt}
int n = -1; Vup|*d2r0E
try{ -KfMKN~
oSavedFile.write(b,nStart,nLen); woF{O)~X
n = nLen; )J2UNIgN
} ~=<uYv?0s
catch(IOException e) " RIt
{ !lA~;F
e.printStackTrace (); *y$CDv
} B]mMwqM#
3C'6i
$vn)(zn+
return n; Bgp%hK
} P{Q$(rOe
*i!t&s
1u(n[<WtT_
} {Z Ld_VGW
IGab~`c-[
DJqJ6z:'
/* zsR5"Vi=
**SiteInfoBean.java =.JcIT'
*/ dP>FXgY
package NetFox; gv i!|!M=
# @7I
)n[=)"rf
public class SiteInfoBean { 09{s'
a4Z e!l(
'+'h^
private String sSiteURL; //Site's URL @hrIu" '!
private String sFilePath; //Saved File's Path ikb77?.
private String sFileName; //Saved File's Name \((5Sd
private int nSplitter; //Count of Splited Downloading File B@ msGb C
tCA0H\';
W1ndb:
public SiteInfoBean() rj?c
{//nSplitter的缺省值为5 u:B=lZ[
//default value of nSplitter is 5 /;!I.|j
this("","","",5); Xn>>hzj-x?
} pRUQMPn (
6z:/ma^
SwaPRAF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0F%?<: &
{ yL -}E
sSiteURL= sURL; O`aNNy
sFilePath = sPath; \MPbG$ ^
sFileName = sName; 2]FRIy d
this.nSplitter = nSpiltter; tCPK_Wws?Z
"5?1S-Vl
PzhC *" i}
} 3Wx\Liw,
C@<gCMj,"
#7}YSfm^6
public String getSSiteURL() xr7M#n
{ a`?Vc}&
return sSiteURL; 2vb qz
} MD3iWgM
^&$86-PB/
Tks"GlE*D
public void setSSiteURL(String value) '$J M2 u
{ {) sE;p-
sSiteURL = value; }U4mXkZF
} iM9^.
xO,;4uE
W5~!)Ec
public String getSFilePath() :_=YH+bZ
{ 6s ~!B{Q
return sFilePath; WT3g31
} X\i;j!;d
S/RChg_L5
(Jk[%_b>_
public void setSFilePath(String value) JZE@W-2
{ j%J>LeTca
sFilePath = value; ;18u02z^
} /Ei e5p
|2rOV&@l9
'C#[iRG4
public String getSFileName() k2PK4Ua_}q
{ Z)@[N 6\?
return sFileName; >ffC?5+
} 9]1LwX!M2
*X}2
s#")hMJQ
public void setSFileName(String value) .b^!f<j
{ >.G#\w
sFileName = value; 7u5H o`
} 3f~znO
2iOYC0`!
]D=fvvST
public int getNSplitter() W/~q%\M {
{ )UVekkq>Q
return nSplitter; i->G{_gH
} !@y/{~Gu
[X8EfU}
#v9+9X`1L
public void setNSplitter(int nCount) =qL^#h83y
{ 2~B5?(g
nSplitter = nCount; ugTnz$
} \=xS?(v!
} RZ ?SiwE
|zd5P
w|*D{`O
/* rls{~ZRl
**Utility.java u]ps-R_$G
*/ +4rd N\.
package NetFox; m| 7v76(
oJ/=&c
sBqOcy
public class Utility { VwK7\jV
Ai5+ ;8z+
K\s<<dRa
public Utility() wwJs_f\
{ j#Lj<jX!xR
FP*kA_z$
FT-=^VA\
} LB}J7yEQvj
xe3Jxo!U
//线程睡眠 !T8sWMY
public static void sleep(int nSecond) 1rLxF{,
{ lLglF4
try{ a$bE2'cb
Thread.sleep(nSecond); |+>U91!
} I9`ZK2S
catch(Exception e) 9jNh%raG|
{ tAujm*|&
e.printStackTrace (); ^),t=!;p
} YRd`G3J
} >RpMw!NT
k72NXagh
//日志 YNKvR
public static void log(String sMsg) W ,v0~
{ wqJl[~O$
System.err.println(sMsg); pEX Q
} 1&9w]\Ae7l
e#F3KLSL`
W{j(=<|<
public static void log(int sMsg) N%e^2O)
{ ]&P 4QT)f
System.err.println(sMsg); HNlW.y"
} $'<$:;4b3
} VRSBf;?
*m`x/_y+
M 8(w+h{
/* Dqd2e&a\
**TestMethod.java \0&$n
*/ %5@> nC?`[
package NetFox; :1@jl2,
kr!>rqN5
N3oa!PE
public class TestMethod { !:tr\L {
I#7H)^us
D-x*RRkpp
public TestMethod() Ra:UnA
{ ///xx/weblogic60b2_win.exe vmo!
try{ [ <k&]Kv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `G:hC5B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j8rxhToC
SiteFileFetch fileFetch = new SiteFileFetch(bean); h%v qt~0
fileFetch.start(); mC?}:WM@
} 1|:;~9n<t
catch(Exception e){e.printStackTrace ();} uX&h~qE/
lZ <D,&
?Jgqb3+!o
} C 20VSwd
}h8U.k?v
F5M|QX@-
public static void main(String[] args) 9F~5Ht
{ X\*H7;k,
new TestMethod(); "1%k"+&
} <DII%7q,6/
} PGVP0H+RV
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