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)); e0`5PVJ
} Vv*](iM
for(int i=0;i<nEndPos.length-1;i++) Gg5+Ap D
{ > |(L3UA9
nEndPos = nStartPos[i+1]; @gjA8mL
} e^orqw/I
nEndPos[nEndPos.length-1] = nFileLength; oN=>U"<\1
} bA/'IF+
} Z4D[nPm$
6Vu)
rWip[>^
//启动子线程 B[;aNyd<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6rN.)dL.#N
for(int i=0;i<nStartPos.length;i++) [(Ihue
{ H~lvUHN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?l^NKbw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8]xYE19=
nStartPos,nEndPos,i); S.*LsrSV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _''9-t;n,
fileSplitterFetch.start(); k6(0:/C
} l6pvQ|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v`r*Yok;`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |L(h+/>aWX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l|K$6>80
nEndPos = " + nFileLength); HD>UTX`&mc
// fileSplitterFetch[nPos.length-1].start(); >yqFO
I"HA( +G
f^G-ba
//等待子线程结束 Er<!8;{?
//int count = 0; oVIc^yk5a
//是否结束while循环 RdLk85<n
boolean breakWhile = false; `':G92}#
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NwNjB w%v
while(!bStop) g\G}b
{ 1i@a? 27|
write_nPos(); 8_T9[]7V8
Utility.sleep(500); gm7 [m}
breakWhile = true; \-r"%@OkW
|F&02f!]@
Y {|is2M9'
for(int i=0;i<nStartPos.length;i++) !xEGN@
{ FM<`\d'
if(!fileSplitterFetch.bDownOver) wnHfjF
{ v>0} v)<v
breakWhile = false; RSup_4A
break; !JA//{?
} _Oy;:XN
} N,4hh?
if(breakWhile) O[F
break; /&zlC{:G92
R_Z9aQ
TVAa/_y2`
//count++; Fmzkbt~oe
//if(count>4) XUTsW,WC
// siteStop(); o&>aYlXd
} Hh* KcIRX
UHBMl>~z
#q6#nfi"
System.err.println("文件下载结束！"); >O~
} qI*7ToBJ
catch(Exception e){e.printStackTrace ();} hp}JKj@
} -!IeP]n#P
Dw<bLSaW&
,6SzW+L7
//获得文件长度 Ht|"91ZC5
public long getFileSize() :}-izd)/j
{ C~T*Wlk
int nFileLength = -1; ogJ *
try{ $>rKm
URL url = new URL(siteInfoBean.getSSiteURL()); +HlZ?1g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9hjzOJPuga
httpConnection.setRequestProperty("User-Agent","NetFox"); Zm6|aHx8v
+g_m|LF
p;~oIy\,
int responseCode=httpConnection.getResponseCode(); .pIO<ZAFT
if(responseCode>=400) "%#CMCE|f
{ 5E =!L g
processErrorCode(responseCode); &.P G2f*
return -2; //-2 represent access is error HF*j=qt!
} n_kE
'1X^@]+6
]U,m 1
String sHeader; @?bY,
=ba1::18
5-UrHbpCZ#
for(int i=1;;i++) &FWz7O>1
{ DC0ON`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?*'0;K13
//Utility.log(in.readLine()); K?>sP%m)
sHeader=httpConnection.getHeaderFieldKey(i); 9(lcQuE9
if(sHeader!=null) RV%)~S@!R
{ <7`U1DR=
if(sHeader.equals("Content-Length")) 4<Kxo\\S
{ M9?f`9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F:8@ ]tA&
break; Q+s2S>U{v
} AOef1^S=
} eu'~(_2
else ahFK^ #s
break; <MoyL1=
} ijKQ`}JA
} dtig_s,)D
catch(IOException e){e.printStackTrace ();} ]d.e(yCuE
catch(Exception e){e.printStackTrace ();} (6&"(}Pai
O)D$UG\<
Xh}G=1}
Utility.log(nFileLength); 6VLo4bq 5
,h<xY>
pUa\YO1J
return nFileLength; yatZAl(B
} M5 ^qc
}:(;mW8 D
z>)lp$
//保存下载信息（文件指针位置） `nY.&YT
private void write_nPos() >X*Y jv:r
{ NdrR+t^#
try{ yQf(/Uxk*x
output = new DataOutputStream(new FileOutputStream(tmpFile)); Adgfo)X5
output.writeInt(nStartPos.length); ^DVryeLD
for(int i=0;i<nStartPos.length;i++) k106fT]eX
{ #Y'ewu;qJ
// output.writeLong(nPos); p-H}NQ\
output.writeLong(fileSplitterFetch.nStartPos); T[MDjhv'
output.writeLong(fileSplitterFetch.nEndPos); tToP7q^
} \UZ7_\
output.close(); O`T_'.Lk
} ^fmuBe}d{
catch(IOException e){e.printStackTrace ();} $i1:--~2\
catch(Exception e){e.printStackTrace ();} 4vV\vXT*
} wj5,_d)
b*ja,I4
;te( {u+
//读取保存的下载信息（文件指针位置） T8d=@8g,%
private void read_nPos() Dw$RHogb~y
{ F<Xtp8
try{ a'r1or4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }KT$J G?
int nCount = input.readInt(); UhJ!7Ws$
nStartPos = new long[nCount]; 59i2*<k
nEndPos = new long[nCount]; E6M*o+Y
for(int i=0;i<nStartPos.length;i++) <'\!
{ 7spZe"
nStartPos = input.readLong(); 4*HBCzr7[
nEndPos = input.readLong(); N6> rU
} n3j_=(
input.close(); u=Xpu,q
} ZrB(!L~7
catch(IOException e){e.printStackTrace ();} ct<XKqbI
catch(Exception e){e.printStackTrace ();} AnK X4Q
} D !{e
cp0yr:~
"=LeHY=9
private void processErrorCode(int nErrorCode) EAy@kzY?
{ /:"^,i\t
System.err.println("Error Code : " + nErrorCode); ]c bXI
} R7O<>kt
^E.mG>
e X6o7a
//停止文件下载 Q<KF<K'0hg
public void siteStop() GMB3`&qh
{ ewWw
bStop = true; gtT&97tT<
for(int i=0;i<nStartPos.length;i++) ddd2w
fileSplitterFetch.splitterStop(); Ya(3Z_f+VZ
2p4iir
Z#D*HAd`
} z?F`)}
} e)m6xiZ
//负责部分文件的抓取 :))&"GY
**FileSplitterFetch.java 1Zi` \N4T
*/ Y0J:c?,
package NetFox; +SW|/oIU
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l/"!}wF
import java.io.*; /a)^)
import java.net.*; LROrhO
P1Eg%Y6
{u-J?(s}
public class FileSplitterFetch extends Thread { 6']G HDK
#{#k;va
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String sURL; //File URL e/#6qCE
long nStartPos; //File Snippet Start Position 1$`|$V1
long nEndPos; //File Snippet End Position L\5:od[EP
int nThreadID; //Thread's ID /Ak\Q5O'3
boolean bDownOver = false; //Downing is over <0? r# }
boolean bStop = false; //Stop identical rY8(`a
FileAccessI fileAccessI = null; //File Access interface S9ic4rcd
rBi6AM/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }E[vW
{ dvz6
this.sURL = sURL; yu&muCA
this.nStartPos = nStart; IO]tO[P#
this.nEndPos = nEnd; Qwve-[
nThreadID = id; j5A>aj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (44L8)I.D
} )>U"WZ'<
#2$wI^O
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public void run() J<4_<.o(a
{ ynZEJKo
while(nStartPos < nEndPos && !bStop) &9z&#`AY]>
{ eu~ u-}.
U<>@)0~7g!
ZS=;)
try{ q&_\A0
URL url = new URL(sURL); @&%/<|4P5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /-t!)_zvw
httpConnection.setRequestProperty("User-Agent","NetFox"); {d]B+'
String sProperty = "bytes="+nStartPos+"-"; }2:q#}"
httpConnection.setRequestProperty("RANGE",sProperty); dLeos9M:
Utility.log(sProperty); XKDX*x G
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9I$}=&"
InputStream input = httpConnection.getInputStream(); :eT\XtxM~{
//logResponseHead(httpConnection); fY?:SPR+
EyA(W;r.
qR_Np5nHF
byte[] b = new byte[1024]; }Kp$/CYd
int nRead; 9_.pLLx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @F*z/E}e
{ 3orL;(.G
nStartPos += fileAccessI.write(b,0,nRead); 5|>ms)[RQ
//if(nThreadID == 1) i)$+#N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j]`hy"
} ~D`R"vzw=
uFhPNR2l
jTZi< Y:bB
Utility.log("Thread " + nThreadID + " is over!"); 9j5|o([J
bDownOver = true; GoH.0eQ^
//nPos = fileAccessI.write (b,0,nRead); dm40qj
} [O|c3;
catch(Exception e){e.printStackTrace ();} Qh6vH9(D
} j9GKz1
} e'c3.sQ|?
'HCRi Z<
;l<Hen*
//打印回应的头信息 tFX<"cAvK
public void logResponseHead(HttpURLConnection con) #3eI4KJ4+l
{ E>gLUMG$
for(int i=1;;i++) A7&/3C6{H
{ p!)tA
String header=con.getHeaderFieldKey(i); vb]uO ' l
if(header!=null) W(?J,8>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2"j&_$#l5X
Utility.log(header+" : "+con.getHeaderField(header)); i,%N#
else Pgq(yPC
break; 2 e#"JZ=
} l0qHoM,1Y[
} rc7c$3#X
=|dm#w_L"
6#Y]^%?uy
public void splitterStop() <<Y]P+uU
{ #pPR>,4
bStop = true; E[=&6T4
} w(X}
*CAz_s<
.y_~mr&d
} )"|wWu
CdcBE.%<
p]?eIovi
/* zf5%|7o
**FileAccess.java ZCb@!V}=
*//文件访问(定位，写) <{hB&4oL
package NetFox; w^n&S=E E~
import java.io.*; =knLkbiq7,
1=E}X5
,?Vxcr
public class FileAccessI implements Serializable{ {{[@ X
z|Xt'?9&n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z0D&ayzkh^
RandomAccessFile oSavedFile; T nyLVIP
long nPos; dVGcth;
Z=%u:K}[
-em3 #V
public FileAccessI() throws IOException q$IU!I4
{ M195[]
this("",0); TaKHr$h
} .L^;aL
eI|~neh
YnDaBpx
public FileAccessI(String sName,long nPos) throws IOException MrOtsX
{ ^L Xr4
oSavedFile = new RandomAccessFile(sName,"rw"); D62'bFB^
this.nPos = nPos; N"Y%*BkH
oSavedFile.seek(nPos); 6& hiW]Adm
} 7Wiwnv_"
O8rd*+
|Xd&aQ
public synchronized int write(byte[] b,int nStart,int nLen) sk0/3X*Q%
{ vp d!|/
int n = -1; gu'+kw
try{ 7)Tix7:9S;
oSavedFile.write(b,nStart,nLen); #^ .G^d(=
n = nLen; `ZP[-:`
} t*6C?zEAU
catch(IOException e) f^5sJ0;%
{ Y2N$&]O{
e.printStackTrace (); 9c1q:>|
} $U. 2"
vt5>>rl
!y!s/i&P%
return n; 3=UufI
} iU~d2R+
<8Z%'C6d
"/UPq6
} M$f_I +
rfZg
CPP9=CoR37
/* SL^%Zh/~
**SiteInfoBean.java kjQI=:i=
*/ AP=SCq;
package NetFox; cmaha%3d
qPhVc9D#
AO5a
public class SiteInfoBean { HJ!)&xT
y4!fu<[i
o5Knot)Oy
private String sSiteURL; //Site's URL [r'hX#
private String sFilePath; //Saved File's Path x0TE+rf5
private String sFileName; //Saved File's Name Gt!Hm(
private int nSplitter; //Count of Splited Downloading File )coA30YR
Th~pju
(ueH@A"9;
public SiteInfoBean() }JT&lyO< b
{//nSplitter的缺省值为5 pBQ[lPCY/
//default value of nSplitter is 5 F1`mq2^@
this("","","",5); X&K,,C
} +ZBj_Vw*|
R~N%sn
*y>|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F{}:e QD
{ bs?4|#[K
sSiteURL= sURL; *S Z]xrs
sFilePath = sPath; C{ Z*5)
sFileName = sName; (hv}K*c{
this.nSplitter = nSpiltter; R/^;,.
o9v9 bL+X
~i}/
} =)]RD%Oq
91#n Aj%
#e9XU:9@g
public String getSSiteURL() T(~^X-k
{ BTE&7/i21
return sSiteURL; SC2g5i`
} H"2,Q T
HI)U6.'
i l%9j
public void setSSiteURL(String value) _b=})**
{ x6=tS
sSiteURL = value; /J,&G: Er
} z]O>`50Q
2Ju,P_<dt
6|%HCxWO
public String getSFilePath() Ax!fvcsN
{ O}7aX '
return sFilePath; ):Ekf2
} s: MJ{r(s
$5>x)jr:w+
,z0E2
public void setSFilePath(String value) +6Vu]96=KC
{ 81wmKqDEs
sFilePath = value; mOYXd,xd
} 9x9E+DG#(
Y XxWu8
6AmFl<
public String getSFileName() )#Y:Bj7H@2
{ s|"4!{It
return sFileName; %E2C4UbY
} q.lh
UAdj[m61
Q9t.*+
public void setSFileName(String value) j!`2Z@
{ `P9%[8`C 9
sFileName = value; h6(L22Hn
} z.kBQ{P
VH.}}RS%
hM`*-+Zb
public int getNSplitter() *Kw/ilI
{ B&H [z
return nSplitter; _Hq)mF
} gr$H?|n l
)i>T\B
DZ|/#- k
public void setNSplitter(int nCount) 3bB%@^<
{ u+e.{Z!
nSplitter = nCount; oRCD8b?
} aeF^&F0
} 7kidPAhY
W-ECmw(
rYr.mX
/* cNqw(\rr
**Utility.java :y[tZ&*<_?
*/ Q|cA8Fn
package NetFox; Ad`jV_z
1Aa=&B2
Yy0m &3[
public class Utility { <8/lHQ^\)
w+tO@
rx;zd?
public Utility() k$} 6Qd
{ WR"p2=
mdHC{sp
aMjCqu05
} jl4rEzVu
bjq2XP?LL
//线程睡眠 Mxe
public static void sleep(int nSecond) o>Z+=&BZ@a
{ $(%t^8{a~G
try{ sQe>LNp,G
Thread.sleep(nSecond); 5=Y\d,SS"
} bpeWK&
catch(Exception e) gs77")K&
{ \Tj(]
e.printStackTrace (); bga2{<VF
} *,DBRJ_*7
} zHCz[jlrMq
U=bZy,FT$
//日志 7e&%R4{b
public static void log(String sMsg) v<Ux+-
{ o,RLaS,BK'
System.err.println(sMsg); nS1D&;#Y
} c =i6
n_*k e
Nm=W?i
public static void log(int sMsg) nEm+cHHo?
{ vd<" G}
System.err.println(sMsg); Ws`P(WHm
} ,*Yu~4
} }KHdlhD
-gV'z5
W;C41>^?/
/* ",T-'>h$2R
**TestMethod.java 1jozM"H7Q
*/ <tg>1,C
package NetFox; _\LAWQ|M4[
vH#^|u
Ofg-gCF8
public class TestMethod { ~(`iRxK
kSw.Q2ao
~dK)U*Q
public TestMethod() IPnbR)[%
{ ///xx/weblogic60b2_win.exe VscEdtkd
try{ uIvE~<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6^.<5SJ}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O(PG"c
SiteFileFetch fileFetch = new SiteFileFetch(bean); u-7/4Y)c
fileFetch.start(); 7>J8\=
} #\$R^u]!
catch(Exception e){e.printStackTrace ();} 5!G}*u.
I%whM~M1+
HLU'1As65
} JQ8wL _C>
X}xy v
d1#;>MiU
public static void main(String[] args) ~8Z0{^
{ :_Y@,CpIEg
new TestMethod(); GKwm %A
} PDo%ob\Ym
} GRb"jF>ut
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