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)); ]pZxbs&Vb
} D{]t50a.
for(int i=0;i<nEndPos.length-1;i++) Fo=hL
{ _k0X)N+li
nEndPos = nStartPos[i+1]; \B0,?_i
} (o!v,=# 6{
nEndPos[nEndPos.length-1] = nFileLength; ]"jJgO^
} 7>Af"1$g
} 7gLN7_2
#bqc}h9
_Ra$"j
//启动子线程 BM(8+Wj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;^9Ao>(?y
for(int i=0;i<nStartPos.length;i++) d+1q[,-
{ _&Hq`KJm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I.[2-~yf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vPm&0,R*y:
nStartPos,nEndPos,i); 5AvbKT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Ts6M,Fpp
fileSplitterFetch.start(); ? 1OZEzA!
} ]wH,534
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F__j]}?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x<m{B@3T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gEVN;G'B<=
nEndPos = " + nFileLength); N3D{t\hg
// fileSplitterFetch[nPos.length-1].start(); Sn I-dXNF
MeXzWLH
He#5d!cf:M
//等待子线程结束 _vQtV]
//int count = 0; *}pl
//是否结束while循环 j-egsKR
boolean breakWhile = false; i8F^ N=
VJK?"mX
u&q RK>wLa
while(!bStop) aZ[ aZU
{ N$8do?
write_nPos(); 0b)^#+
Utility.sleep(500); DrfOz#a0Uu
breakWhile = true; O]"3o,/]G
ea"!:cL(g
}:5_vH0
for(int i=0;i<nStartPos.length;i++) OLThi[Yn
{ G~SgI>Q
if(!fileSplitterFetch.bDownOver) 6}Se$XMl
{ O~E6"vQ
breakWhile = false; 83 O+`f
break; (=hXt=hZ
} 4eZ
} BoJYP
if(breakWhile) aR3R,6ec
break; I9sx*'
zG\g{cB
Q_ zGs6
//count++; p$>e{-u
//if(count>4) >EVlMt27'
// siteStop(); j"FX ?|4
} q|*}>=NX
OQ[E-%v1 R
]}4{|& e
System.err.println("文件下载结束！"); h5+qP"n!?q
} aNZJs<3;'D
catch(Exception e){e.printStackTrace ();} t`PA85.|d
} m!{}Y]FZn
W<J".2D
'dE G\?v9
//获得文件长度 ^%)H;
public long getFileSize() 1b4aY> Z
{ +-b:XeHSZ
int nFileLength = -1; <SiD m-=E
try{ (~YFm"S
URL url = new URL(siteInfoBean.getSSiteURL()); 1!u}~E_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TTg>g~t`
httpConnection.setRequestProperty("User-Agent","NetFox"); -7GF2 @
.C]V==z`[4
]SNA2?q
int responseCode=httpConnection.getResponseCode(); 9fk@C/$
if(responseCode>=400) VieX5
{ q#fj?`k
processErrorCode(responseCode); \(y6o}aW
return -2; //-2 represent access is error v3b[08 F
} m$T?~oo
l2v4SvbX
B7:8%r/
String sHeader; rlj @'
=@#[@Ia
UQGOCP_
for(int i=1;;i++) yo)a_rY
{ ~vD7BO`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 19 h7 M
//Utility.log(in.readLine()); X#l]%IrW!
sHeader=httpConnection.getHeaderFieldKey(i); Z]$RO
if(sHeader!=null) # 2As-9
{ .C avb
if(sHeader.equals("Content-Length")) ;^5d^-T
{ ISHNeO8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C$X )I~M
break; (p1y/"Xh
} w7b?ve3-
} W"9?D
else Evd>s
break; wGd4:W
} OrXx0Hn
} P;%4Imq3
catch(IOException e){e.printStackTrace ();} :e-&,K
catch(Exception e){e.printStackTrace ();} .@0i,7S
:t &ib}v
s: c
Utility.log(nFileLength); U#oe8(?#
#q{i<E 07
P8DT2|Z6f]
return nFileLength; 2ql7*g?Uq@
} jEQr{X7bEL
z/bJDSQ
SB#YV
//保存下载信息（文件指针位置） #JAU5d
private void write_nPos() 28l",j)S
{ '}a[9v76
try{ ?!H<V@a
output = new DataOutputStream(new FileOutputStream(tmpFile)); S>~QuCMY
output.writeInt(nStartPos.length); ZyE2=w7n
for(int i=0;i<nStartPos.length;i++) "hRw_<
{ zx7*Bnu0
// output.writeLong(nPos); M[5zn
output.writeLong(fileSplitterFetch.nStartPos); vF, !8e'v
output.writeLong(fileSplitterFetch.nEndPos); o'.6gZ gk
} Ro+/=*ql~
output.close(); vt`hY4
} uHdrHP
catch(IOException e){e.printStackTrace ();} E.v~<[g
catch(Exception e){e.printStackTrace ();} &wj;:f
} `Q!|/B
~__]E53F
Ya] qo]
//读取保存的下载信息（文件指针位置） "rz|sbj
private void read_nPos() #84pRU~
{ Q2;zve&Dl
try{ \XR%pC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [V`j@dV
int nCount = input.readInt(); pyK|zvr-r
nStartPos = new long[nCount]; 9WQC\/w
nEndPos = new long[nCount]; +O23@G?x
for(int i=0;i<nStartPos.length;i++) }?B=R#5
{ xw-x<7
nStartPos = input.readLong(); LPbZ.
nEndPos = input.readLong(); ocwRU0+j
} -d\O{{%>.z
input.close(); <Vp7G%"'W
} gO-C[j/
catch(IOException e){e.printStackTrace ();} Yo:l@(
catch(Exception e){e.printStackTrace ();} .?b2Bd!MC
} =LJc8@<:f
gH-e0134%
>'eOzMBn
private void processErrorCode(int nErrorCode) | ]`gps
{ qPdNI1 |
System.err.println("Error Code : " + nErrorCode); lp5`Kw\
} $NP5Z0v7
s)%RmsdL
'>[KVvm
//停止文件下载 {Q8DPkW
public void siteStop() KU[eY}
{ |i-Qfpn
bStop = true; ,-Fhb~u
for(int i=0;i<nStartPos.length;i++) h+|3\>/@9{
fileSplitterFetch.splitterStop(); -bSe=09;S|
e47JLW&b
MP,l*wVd
} GqhnE>
} yG58?5\9
//负责部分文件的抓取 cA ;'~[
**FileSplitterFetch.java U:>'^tkp
*/ j[YzBXd V
package NetFox; }gL9G
"Iu[)O%
H n+1I
import java.io.*; ws5x53K
import java.net.*; J=67As
CtVY;eG
cH6ie?KvAo
public class FileSplitterFetch extends Thread { vBsd.2t~
w3:WvA5jt
BR\%aU$u
String sURL; //File URL &|P@$O>
long nStartPos; //File Snippet Start Position wJh|$Vn
long nEndPos; //File Snippet End Position hb9X<N+p
int nThreadID; //Thread's ID %a+X\\v2
boolean bDownOver = false; //Downing is over a8aEZ724
boolean bStop = false; //Stop identical vTjgW?9
FileAccessI fileAccessI = null; //File Access interface 5bFE;Y;
49}yw3-
OlhfBu)~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WZ5[tZf
{ ~\/>b}^uf'
this.sURL = sURL; ?RvXO'ml
this.nStartPos = nStart; >]Hz-2b
this.nEndPos = nEnd; ]CH@T9d5V
nThreadID = id; {rGq|Bj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ken|!rL
} T^NY|Y/
d9|dHJf
qAm$yfYs`
public void run() &'Qz
{ c&)H
while(nStartPos < nEndPos && !bStop) uOc>~ITPS
{ ]4\^>
:gY$/1SYD
*wP8)yv7
try{ dra'1E
URL url = new URL(sURL); GmtMA|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :ORCsl6-
httpConnection.setRequestProperty("User-Agent","NetFox"); ^G=wRtS
String sProperty = "bytes="+nStartPos+"-"; 'T7JXV5
httpConnection.setRequestProperty("RANGE",sProperty); Gk,{{:M:5
Utility.log(sProperty); v83uGEq(
WM: ~P$%cx
$/],QD_;"
InputStream input = httpConnection.getInputStream(); p+;Re2Uyg
//logResponseHead(httpConnection); 1O45M/5\o
\8Mkb]QA
>OE.6)'Rm
byte[] b = new byte[1024]; x+|Fw d
int nRead; SDiZOypS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _baqN!N
{ |`s}PcV
nStartPos += fileAccessI.write(b,0,nRead); mW1Sd#0
//if(nThreadID == 1) Ol9U^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FFbMG:>:
} q?8MKf[N
v6oPAqj,r
<,Sy:>:"
Utility.log("Thread " + nThreadID + " is over!"); @S?.`o
bDownOver = true; Q6,rY(b6
//nPos = fileAccessI.write (b,0,nRead); ixBM>mRK
} OnH>g"
catch(Exception e){e.printStackTrace ();} m<8j' [+
} seHwn'Jn
} kR^7Z7+#*
7;;W{W%
k(=\&T
//打印回应的头信息 tA#X@HIE
public void logResponseHead(HttpURLConnection con) H24g+<Tv
{ =G}_PRn
for(int i=1;;i++) =t@m:
{ u>&\@?(
String header=con.getHeaderFieldKey(i); [2 2IF
if(header!=null) 2-llT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (m)%5*:
Utility.log(header+" : "+con.getHeaderField(header)); eN/sW!:P|
else WES#ZYtT
break; :1aL ?
} Xe1P- 60
} #&Is GyU
?IhB-fd>@
p*qPcuAA
public void splitterStop() b{cU<;G)y.
{ *l+Cl%e
bStop = true; 6|;Uq'
} Q!'qC*Gyfn
kfrY1
^vni&sJ
} m&Yi!7@(
"@ E3MTW
}iiHr|l3
/* #@f[bP}a
**FileAccess.java ,/2LY4` 5
*//文件访问(定位，写) lK(Fg
package NetFox; 1{PG>W
import java.io.*; "v]%3i.* -
R.RSQk7;
$:bih4@>
public class FileAccessI implements Serializable{ \~DM
Le#spvV3J|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FfFak@H
RandomAccessFile oSavedFile; :0~QRc-u
long nPos; `DW2spd
k$7Z^~?Fz
lP_db&
public FileAccessI() throws IOException e@]-D FG
{ 2xxB\J
this("",0); TkRP3_b
} S\ ,mR4:
zF&=U`v
v}(6 <wnnS
public FileAccessI(String sName,long nPos) throws IOException ?vtX"Fdz
{ NC"yDWnO'
oSavedFile = new RandomAccessFile(sName,"rw"); i!H!;z#
this.nPos = nPos; OSDy'@
oSavedFile.seek(nPos); 6(V /yn~
} >s EjR!
-j2 (R?a
`dkV_ O0
public synchronized int write(byte[] b,int nStart,int nLen) #bnb': f
{ EtJ8^[u2J
int n = -1; E5GJi
try{ `N87h"
oSavedFile.write(b,nStart,nLen); g.DLfwI|
n = nLen; 't (O$
} l]LxL
catch(IOException e) P,xwSvO#M
{ CXaWgxlK:a
e.printStackTrace (); JMa3btLy(
} C"pB"^0
</~ 6f(mg
+Ic ~ f1zh
return n; J./d!an
} ocRdbmS
\Ad7 Gi~
=t0tK}Y+4
} y-aRXF=W
%5'6Tj
<^R{U&Z@
/* %j,iAUE<
**SiteInfoBean.java J5p8nmb
*/ Wr~yK? : ]
package NetFox; Ub$n |xn
#?O&
cu9Qwm
public class SiteInfoBean { M4f;/`w
|i%2%V#
Sb&lhgW]c
private String sSiteURL; //Site's URL @4+#Xd7"
private String sFilePath; //Saved File's Path tNaL;0#Tx
private String sFileName; //Saved File's Name @r7:NU}
private int nSplitter; //Count of Splited Downloading File epD?K
wTq{sW&
}^ FulsC
public SiteInfoBean() PD[z#T!'
{//nSplitter的缺省值为5 R[[ ,q:4
//default value of nSplitter is 5 C"uahP[Y
this("","","",5); Sr Ca3PA
} 0"WDH)7hJ
wFS2P+e;X
Tenf:Hm/k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $9!D\N,}]C
{ cWAtju?L;
sSiteURL= sURL; "9y( }
sFilePath = sPath; f>9s!Hpu_
sFileName = sName; -#:zsu
this.nSplitter = nSpiltter; ^c}J,tZ]
-%c<IX>z9
7N8H)X
} q?j|K|%
"?}uQ5f
5N7H{vT_
public String getSSiteURL() JgRYljQi2
{ _c(4o:
return sSiteURL; Td\o9
} ^_+XDO
)Di \_/G
I s57F4[}
public void setSSiteURL(String value) dE`-\J
{ |AhF7Mj*
sSiteURL = value; /1w2ehE<
} j+4H}XyE
El2e~l9
T? ,P*l
public String getSFilePath() {r85l\u)Q\
{ xG2+(f#C1
return sFilePath; d' >>E
} &K+0xnUH
_~'+Qe_o$5
9SQ4cv*2
public void setSFilePath(String value) X|LxV]
{ ksR1kvTm
sFilePath = value; ?`_jFj+<\S
} U977#MXf
TCKu,}s
Rf-[svA
public String getSFileName() =}!Mf'
{ [V8fu qE>
return sFileName; (oz$B0HO:
} vdDludEv
+UN<Zp7I/
0IkM
public void setSFileName(String value) :aLT0q!K
{ ;lX(}2tXW
sFileName = value; una%[jTc
} sM[I4.A3
}G<T:(a
&;TJ~r#K
public int getNSplitter() `6Qdfmk=
{ J8a*s`ik
return nSplitter; FyoEQ%.bI
} qml2XJ>
a&{X!:X
<+j)P4O4
public void setNSplitter(int nCount) {:nQl}
{ LjFqZrH
nSplitter = nCount; C#V ~Y
} h0vob_Fdl
} RC#C\S6
BKa- k!
#:x4DvDkR
/* V D?*h
**Utility.java ?|{XZQ~
*/ J T#d(Y
package NetFox; 2Se?J)MN
H5cV5E0
Z=5qX2fy1*
public class Utility { $h[QQ-
Lw7=+h)
X.F^$
public Utility() <Peebv&v
{ RZpcXv
HS>f1!
nR>r2wMk@
} b IW'c_ ,
ma$Prd
//线程睡眠 s^OO^%b
public static void sleep(int nSecond) x3ERCqTR
{ \'CN
try{ 3ss6_xd+
Thread.sleep(nSecond); ^I6^g
} 'uDjFQX
catch(Exception e) 5BkV aF7Th
{ $2DuB
e.printStackTrace (); >evS}O6
} iJxQB\x
} )QagS.L{z
nfW&1a
//日志 Z+`{7G?4m
public static void log(String sMsg) +|Hioq*,t
{ g42)7
System.err.println(sMsg); 39F Of
} ! Z`0(d
:4S%'d7
d1@%W;qX!
public static void log(int sMsg) FOwDp0
{ )Rat0$6
System.err.println(sMsg); =$8nUX`
} P #F=c34u
} p,pR!qC>
)?M9|u
g[>\4B9t
/* [OTJVpC
**TestMethod.java o`zr>
*/ depYqYK7G
package NetFox; ]9=h%5Ji>
LWsP ya
_{vkX<s
public class TestMethod { %S` v!*2
"TV(H+1,z
GhY1k";
public TestMethod() l:6,QaT1
{ ///xx/weblogic60b2_win.exe 0,s$T2
try{ '/Bidb?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1QZ&Mj^^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w:Jrmx
SiteFileFetch fileFetch = new SiteFileFetch(bean); 22<0DhJ
fileFetch.start(); N!Qg;(
} BYW^/B Y)
catch(Exception e){e.printStackTrace ();} `s '#
b96%")
<D&)OxEn\
} &~UJf4b|A
i`/+,<
FG3UZVUg9
public static void main(String[] args) 6qe*@o
{ e}@)z3Q<l
new TestMethod(); KV|}#<dD
} V>64/
} ~'5
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